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One Round DKG (#589)
* Upstream GBP, divisor, circuit abstraction, and EC gadgets from FCMP++ * Initial eVRF implementation Not quite done yet. It needs to communicate the resulting points and proofs to extract them from the Pedersen Commitments in order to return those, and then be tested. * Add the openings of the PCs to the eVRF as necessary * Add implementation of secq256k1 * Make DKG Encryption a bit more flexible No longer requires the use of an EncryptionKeyMessage, and allows pre-defined keys for encryption. * Make NUM_BITS an argument for the field macro * Have the eVRF take a Zeroizing private key * Initial eVRF-based DKG * Add embedwards25519 curve * Inline the eVRF into the DKG library Due to how we're handling share encryption, we'd either need two circuits or to dedicate this circuit to the DKG. The latter makes sense at this time. * Add documentation to the eVRF-based DKG * Add paragraph claiming robustness * Update to the new eVRF proof * Finish routing the eVRF functionality Still needs errors and serialization, along with a few other TODOs. * Add initial eVRF DKG test * Improve eVRF DKG Updates how we calculcate verification shares, improves performance when extracting multiple sets of keys, and adds more to the test for it. * Start using a proper error for the eVRF DKG * Resolve various TODOs Supports recovering multiple key shares from the eVRF DKG. Inlines two loops to save 2**16 iterations. Adds support for creating a constant time representation of scalars < NUM_BITS. * Ban zero ECDH keys, document non-zero requirements * Implement eVRF traits, all the way up to the DKG, for secp256k1/ed25519 * Add Ristretto eVRF trait impls * Support participating multiple times in the eVRF DKG * Only participate once per key, not once per key share * Rewrite processor key-gen around the eVRF DKG Still a WIP. * Finish routing the new key gen in the processor Doesn't touch the tests, coordinator, nor Substrate yet. `cargo +nightly fmt && cargo +nightly-2024-07-01 clippy --all-features -p serai-processor` does pass. * Deduplicate and better document in processor key_gen * Update serai-processor tests to the new key gen * Correct amount of yx coefficients, get processor key gen test to pass * Add embedded elliptic curve keys to Substrate * Update processor key gen tests to the eVRF DKG * Have set_keys take signature_participants, not removed_participants Now no one is removed from the DKG. Only `t` people publish the key however. Uses a BitVec for an efficient encoding of the participants. * Update the coordinator binary for the new DKG This does not yet update any tests. * Add sensible Debug to key_gen::[Processor, Coordinator]Message * Have the DKG explicitly declare how to interpolate its shares Removes the hack for MuSig where we multiply keys by the inverse of their lagrange interpolation factor. * Replace Interpolation::None with Interpolation::Constant Allows the MuSig DKG to keep the secret share as the original private key, enabling deriving FROST nonces consistently regardless of the MuSig context. * Get coordinator tests to pass * Update spec to the new DKG * Get clippy to pass across the repo * cargo machete * Add an extra sleep to ensure expected ordering of `Participation`s * Update orchestration * Remove bad panic in coordinator It expected ConfirmationShare to be n-of-n, not t-of-n. * Improve documentation on functions * Update TX size limit We now no longer have to support the ridiculous case of having 49 DKG participations within a 101-of-150 DKG. It does remain quite high due to needing to _sign_ so many times. It'd may be optimal for parties with multiple key shares to independently send their preprocesses/shares (despite the overhead that'll cause with signatures and the transaction structure). * Correct error in the Processor spec document * Update a few comments in the validator-sets pallet * Send/Recv Participation one at a time Sending all, then attempting to receive all in an expected order, wasn't working even with notable delays between sending messages. This points to the mempool not working as expected... * Correct ThresholdKeys serialization in modular-frost test * Updating existing TX size limit test for the new DKG parameters * Increase time allowed for the DKG on the GH CI * Correct construction of signature_participants in serai-client tests Fault identified by akil. * Further contextualize DkgConfirmer by ValidatorSet Caught by a safety check we wouldn't reuse preprocesses across messages. That raises the question of we were prior reusing preprocesses (reusing keys)? Except that'd have caused a variety of signing failures (suggesting we had some staggered timing avoiding it in practice but yes, this was possible in theory). * Add necessary calls to set_embedded_elliptic_curve_key in coordinator set rotation tests * Correct shimmed setting of a secq256k1 key * cargo fmt * Don't use `[0; 32]` for the embedded keys in the coordinator rotation test The key_gen function expects the random values already decided. * Big-endian secq256k1 scalars Also restores the prior, safer, Encryption::register function.
This commit is contained in:
Luke Parker
@@ -0,0 +1,679 @@
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use rand_core::{RngCore, CryptoRng};
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use zeroize::{Zeroize, ZeroizeOnDrop};
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use multiexp::{multiexp, multiexp_vartime};
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use ciphersuite::{group::ff::Field, Ciphersuite};
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use crate::{
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ScalarVector, PointVector, ProofGenerators, PedersenCommitment, PedersenVectorCommitment,
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BatchVerifier,
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transcript::*,
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lincomb::accumulate_vector,
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inner_product::{IpError, IpStatement, IpWitness, P},
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};
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pub use crate::lincomb::{Variable, LinComb};
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/// An Arithmetic Circuit Statement.
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///
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/// Bulletproofs' constraints are of the form
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/// `aL * aR = aO, WL * aL + WR * aR + WO * aO = WV * V + c`.
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///
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/// Generalized Bulletproofs modifies this to
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/// `aL * aR = aO, WL * aL + WR * aR + WO * aO + WCG * C_G + WCH * C_H = WV * V + c`.
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///
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/// We implement the latter, yet represented (for simplicity) as
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/// `aL * aR = aO, WL * aL + WR * aR + WO * aO + WCG * C_G + WCH * C_H + WV * V + c = 0`.
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#[derive(Clone, Debug)]
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pub struct ArithmeticCircuitStatement<'a, C: Ciphersuite> {
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generators: ProofGenerators<'a, C>,
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constraints: Vec<LinComb<C::F>>,
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C: PointVector<C>,
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V: PointVector<C>,
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}
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impl<'a, C: Ciphersuite> Zeroize for ArithmeticCircuitStatement<'a, C> {
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fn zeroize(&mut self) {
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self.constraints.zeroize();
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self.C.zeroize();
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self.V.zeroize();
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}
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}
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/// The witness for an arithmetic circuit statement.
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#[derive(Clone, Debug, Zeroize, ZeroizeOnDrop)]
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pub struct ArithmeticCircuitWitness<C: Ciphersuite> {
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aL: ScalarVector<C::F>,
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aR: ScalarVector<C::F>,
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aO: ScalarVector<C::F>,
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c: Vec<PedersenVectorCommitment<C>>,
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v: Vec<PedersenCommitment<C>>,
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}
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/// An error incurred during arithmetic circuit proof operations.
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#[derive(Clone, Copy, PartialEq, Eq, Debug)]
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pub enum AcError {
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/// The vectors of scalars which are multiplied against each other were of different lengths.
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DifferingLrLengths,
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/// The matrices of constraints are of different lengths.
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InconsistentAmountOfConstraints,
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/// A constraint referred to a non-existent term.
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ConstrainedNonExistentTerm,
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/// A constraint referred to a non-existent commitment.
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ConstrainedNonExistentCommitment,
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/// There weren't enough generators to prove for this statement.
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NotEnoughGenerators,
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/// The witness was inconsistent to the statement.
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///
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/// Sanity checks on the witness are always performed. If the library is compiled with debug
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/// assertions on, the satisfaction of all constraints and validity of the commitmentsd is
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/// additionally checked.
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InconsistentWitness,
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/// There was an error from the inner-product proof.
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Ip(IpError),
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/// The proof wasn't complete and the necessary values could not be read from the transcript.
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IncompleteProof,
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}
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impl<C: Ciphersuite> ArithmeticCircuitWitness<C> {
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/// Constructs a new witness instance.
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pub fn new(
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aL: ScalarVector<C::F>,
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aR: ScalarVector<C::F>,
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c: Vec<PedersenVectorCommitment<C>>,
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v: Vec<PedersenCommitment<C>>,
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) -> Result<Self, AcError> {
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if aL.len() != aR.len() {
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Err(AcError::DifferingLrLengths)?;
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}
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// The Pedersen Vector Commitments don't have their variables' lengths checked as they aren't
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// paired off with each other as aL, aR are
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// The PVC commit function ensures there's enough generators for their amount of terms
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// If there aren't enough/the same generators when this is proven for, it'll trigger
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// InconsistentWitness
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let aO = aL.clone() * &aR;
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Ok(ArithmeticCircuitWitness { aL, aR, aO, c, v })
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}
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}
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struct YzChallenges<C: Ciphersuite> {
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y_inv: ScalarVector<C::F>,
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z: ScalarVector<C::F>,
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}
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impl<'a, C: Ciphersuite> ArithmeticCircuitStatement<'a, C> {
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// The amount of multiplications performed.
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fn n(&self) -> usize {
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self.generators.len()
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}
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// The amount of constraints.
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fn q(&self) -> usize {
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self.constraints.len()
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}
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// The amount of Pedersen vector commitments.
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fn c(&self) -> usize {
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self.C.len()
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}
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// The amount of Pedersen commitments.
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fn m(&self) -> usize {
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self.V.len()
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}
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/// Create a new ArithmeticCircuitStatement for the specified relationship.
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///
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/// The `LinComb`s passed as `constraints` will be bound to evaluate to 0.
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///
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/// The constraints are not transcripted. They're expected to be deterministic from the context
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/// and higher-level statement. If your constraints are variable, you MUST transcript them before
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/// calling prove/verify.
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///
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/// The commitments are expected to have been transcripted extenally to this statement's
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/// invocation. That's practically ensured by taking a `Commitments` struct here, which is only
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/// obtainable via a transcript.
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pub fn new(
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generators: ProofGenerators<'a, C>,
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constraints: Vec<LinComb<C::F>>,
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commitments: Commitments<C>,
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) -> Result<Self, AcError> {
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let Commitments { C, V } = commitments;
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for constraint in &constraints {
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if Some(generators.len()) <= constraint.highest_a_index {
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Err(AcError::ConstrainedNonExistentTerm)?;
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}
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if Some(C.len()) <= constraint.highest_c_index {
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Err(AcError::ConstrainedNonExistentCommitment)?;
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}
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if Some(V.len()) <= constraint.highest_v_index {
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Err(AcError::ConstrainedNonExistentCommitment)?;
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}
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}
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Ok(Self { generators, constraints, C, V })
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}
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fn yz_challenges(&self, y: C::F, z_1: C::F) -> YzChallenges<C> {
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let y_inv = y.invert().unwrap();
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let y_inv = ScalarVector::powers(y_inv, self.n());
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// Powers of z *starting with z**1*
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// We could reuse powers and remove the first element, yet this is cheaper than the shift that
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// would require
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let q = self.q();
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let mut z = ScalarVector(Vec::with_capacity(q));
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z.0.push(z_1);
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for _ in 1 .. q {
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z.0.push(*z.0.last().unwrap() * z_1);
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}
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z.0.truncate(q);
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YzChallenges { y_inv, z }
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}
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/// Prove for this statement/witness.
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pub fn prove<R: RngCore + CryptoRng>(
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self,
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rng: &mut R,
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transcript: &mut Transcript,
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mut witness: ArithmeticCircuitWitness<C>,
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) -> Result<(), AcError> {
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let n = self.n();
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let c = self.c();
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let m = self.m();
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// Check the witness length and pad it to the necessary power of two
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if witness.aL.len() > n {
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Err(AcError::NotEnoughGenerators)?;
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}
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while witness.aL.len() < n {
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witness.aL.0.push(C::F::ZERO);
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witness.aR.0.push(C::F::ZERO);
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witness.aO.0.push(C::F::ZERO);
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}
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for c in &mut witness.c {
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if c.g_values.len() > n {
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Err(AcError::NotEnoughGenerators)?;
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}
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if c.h_values.len() > n {
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Err(AcError::NotEnoughGenerators)?;
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}
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// The Pedersen vector commitments internally have n terms
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while c.g_values.len() < n {
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c.g_values.0.push(C::F::ZERO);
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}
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while c.h_values.len() < n {
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c.h_values.0.push(C::F::ZERO);
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}
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}
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// Check the witness's consistency with the statement
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if (c != witness.c.len()) || (m != witness.v.len()) {
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Err(AcError::InconsistentWitness)?;
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}
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#[cfg(debug_assertions)]
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{
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for (commitment, opening) in self.V.0.iter().zip(witness.v.iter()) {
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if *commitment != opening.commit(self.generators.g(), self.generators.h()) {
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Err(AcError::InconsistentWitness)?;
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}
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}
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for (commitment, opening) in self.C.0.iter().zip(witness.c.iter()) {
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if Some(*commitment) !=
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opening.commit(
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self.generators.g_bold_slice(),
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self.generators.h_bold_slice(),
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self.generators.h(),
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)
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{
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Err(AcError::InconsistentWitness)?;
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}
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}
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for constraint in &self.constraints {
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let eval =
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constraint
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.WL
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.iter()
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.map(|(i, weight)| *weight * witness.aL[*i])
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.chain(constraint.WR.iter().map(|(i, weight)| *weight * witness.aR[*i]))
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.chain(constraint.WO.iter().map(|(i, weight)| *weight * witness.aO[*i]))
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.chain(
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constraint.WCG.iter().zip(&witness.c).flat_map(|(weights, c)| {
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weights.iter().map(|(j, weight)| *weight * c.g_values[*j])
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}),
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)
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.chain(
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constraint.WCH.iter().zip(&witness.c).flat_map(|(weights, c)| {
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weights.iter().map(|(j, weight)| *weight * c.h_values[*j])
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}),
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)
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.chain(constraint.WV.iter().map(|(i, weight)| *weight * witness.v[*i].value))
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.chain(core::iter::once(constraint.c))
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.sum::<C::F>();
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if eval != C::F::ZERO {
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Err(AcError::InconsistentWitness)?;
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}
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}
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}
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let alpha = C::F::random(&mut *rng);
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let beta = C::F::random(&mut *rng);
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let rho = C::F::random(&mut *rng);
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let AI = {
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let alg = witness.aL.0.iter().enumerate().map(|(i, aL)| (*aL, self.generators.g_bold(i)));
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let arh = witness.aR.0.iter().enumerate().map(|(i, aR)| (*aR, self.generators.h_bold(i)));
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let ah = core::iter::once((alpha, self.generators.h()));
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let mut AI_terms = alg.chain(arh).chain(ah).collect::<Vec<_>>();
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let AI = multiexp(&AI_terms);
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AI_terms.zeroize();
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AI
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};
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let AO = {
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let aog = witness.aO.0.iter().enumerate().map(|(i, aO)| (*aO, self.generators.g_bold(i)));
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let bh = core::iter::once((beta, self.generators.h()));
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let mut AO_terms = aog.chain(bh).collect::<Vec<_>>();
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let AO = multiexp(&AO_terms);
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AO_terms.zeroize();
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AO
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};
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let mut sL = ScalarVector(Vec::with_capacity(n));
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let mut sR = ScalarVector(Vec::with_capacity(n));
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for _ in 0 .. n {
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sL.0.push(C::F::random(&mut *rng));
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sR.0.push(C::F::random(&mut *rng));
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}
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let S = {
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let slg = sL.0.iter().enumerate().map(|(i, sL)| (*sL, self.generators.g_bold(i)));
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let srh = sR.0.iter().enumerate().map(|(i, sR)| (*sR, self.generators.h_bold(i)));
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let rh = core::iter::once((rho, self.generators.h()));
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let mut S_terms = slg.chain(srh).chain(rh).collect::<Vec<_>>();
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let S = multiexp(&S_terms);
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S_terms.zeroize();
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S
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};
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transcript.push_point(AI);
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transcript.push_point(AO);
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transcript.push_point(S);
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let y = transcript.challenge();
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let z = transcript.challenge();
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let YzChallenges { y_inv, z } = self.yz_challenges(y, z);
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let y = ScalarVector::powers(y, n);
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// t is a n'-term polynomial
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// While Bulletproofs discuss it as a 6-term polynomial, Generalized Bulletproofs re-defines it
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// as `2(n' + 1)`-term, where `n'` is `2 (c + 1)`.
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// When `c = 0`, `n' = 2`, and t is `6` (which lines up with Bulletproofs having a 6-term
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// polynomial).
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// ni = n'
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let ni = 2 * (c + 1);
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// These indexes are from the Generalized Bulletproofs paper
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#[rustfmt::skip]
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let ilr = ni / 2; // 1 if c = 0
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#[rustfmt::skip]
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let io = ni; // 2 if c = 0
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#[rustfmt::skip]
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let is = ni + 1; // 3 if c = 0
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#[rustfmt::skip]
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let jlr = ni / 2; // 1 if c = 0
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#[rustfmt::skip]
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let jo = 0; // 0 if c = 0
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#[rustfmt::skip]
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let js = ni + 1; // 3 if c = 0
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// If c = 0, these indexes perfectly align with the stated powers of X from the Bulletproofs
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// paper for the following coefficients
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// Declare the l and r polynomials, assigning the traditional coefficients to their positions
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let mut l = vec![];
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let mut r = vec![];
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for _ in 0 .. (is + 1) {
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l.push(ScalarVector::new(0));
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r.push(ScalarVector::new(0));
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}
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|
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let mut l_weights = ScalarVector::new(n);
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let mut r_weights = ScalarVector::new(n);
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let mut o_weights = ScalarVector::new(n);
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for (constraint, z) in self.constraints.iter().zip(&z.0) {
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accumulate_vector(&mut l_weights, &constraint.WL, *z);
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accumulate_vector(&mut r_weights, &constraint.WR, *z);
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accumulate_vector(&mut o_weights, &constraint.WO, *z);
|
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}
|
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|
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l[ilr] = (r_weights * &y_inv) + &witness.aL;
|
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l[io] = witness.aO.clone();
|
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l[is] = sL;
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r[jlr] = l_weights + &(witness.aR.clone() * &y);
|
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r[jo] = o_weights - &y;
|
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r[js] = sR * &y;
|
||||
|
||||
// Pad as expected
|
||||
for l in &mut l {
|
||||
debug_assert!((l.len() == 0) || (l.len() == n));
|
||||
if l.len() == 0 {
|
||||
*l = ScalarVector::new(n);
|
||||
}
|
||||
}
|
||||
for r in &mut r {
|
||||
debug_assert!((r.len() == 0) || (r.len() == n));
|
||||
if r.len() == 0 {
|
||||
*r = ScalarVector::new(n);
|
||||
}
|
||||
}
|
||||
|
||||
// We now fill in the vector commitments
|
||||
// We use unused coefficients of l increasing from 0 (skipping ilr), and unused coefficients of
|
||||
// r decreasing from n' (skipping jlr)
|
||||
|
||||
let mut cg_weights = Vec::with_capacity(witness.c.len());
|
||||
let mut ch_weights = Vec::with_capacity(witness.c.len());
|
||||
for i in 0 .. witness.c.len() {
|
||||
let mut cg = ScalarVector::new(n);
|
||||
let mut ch = ScalarVector::new(n);
|
||||
for (constraint, z) in self.constraints.iter().zip(&z.0) {
|
||||
if let Some(WCG) = constraint.WCG.get(i) {
|
||||
accumulate_vector(&mut cg, WCG, *z);
|
||||
}
|
||||
if let Some(WCH) = constraint.WCH.get(i) {
|
||||
accumulate_vector(&mut ch, WCH, *z);
|
||||
}
|
||||
}
|
||||
cg_weights.push(cg);
|
||||
ch_weights.push(ch);
|
||||
}
|
||||
|
||||
for (i, (c, (cg_weights, ch_weights))) in
|
||||
witness.c.iter().zip(cg_weights.into_iter().zip(ch_weights)).enumerate()
|
||||
{
|
||||
let i = i + 1;
|
||||
let j = ni - i;
|
||||
|
||||
l[i] = c.g_values.clone();
|
||||
l[j] = ch_weights * &y_inv;
|
||||
r[j] = cg_weights;
|
||||
r[i] = (c.h_values.clone() * &y) + &r[i];
|
||||
}
|
||||
|
||||
// Multiply them to obtain t
|
||||
let mut t = ScalarVector::new(1 + (2 * (l.len() - 1)));
|
||||
for (i, l) in l.iter().enumerate() {
|
||||
for (j, r) in r.iter().enumerate() {
|
||||
let new_coeff = i + j;
|
||||
t[new_coeff] += l.inner_product(r.0.iter());
|
||||
}
|
||||
}
|
||||
|
||||
// Per Bulletproofs, calculate masks tau for each t where (i > 0) && (i != 2)
|
||||
// Per Generalized Bulletproofs, calculate masks tau for each t where i != n'
|
||||
// With Bulletproofs, t[0] is zero, hence its omission, yet Generalized Bulletproofs uses it
|
||||
let mut tau_before_ni = vec![];
|
||||
for _ in 0 .. ni {
|
||||
tau_before_ni.push(C::F::random(&mut *rng));
|
||||
}
|
||||
let mut tau_after_ni = vec![];
|
||||
for _ in 0 .. t.0[(ni + 1) ..].len() {
|
||||
tau_after_ni.push(C::F::random(&mut *rng));
|
||||
}
|
||||
// Calculate commitments to the coefficients of t, blinded by tau
|
||||
debug_assert_eq!(t.0[0 .. ni].len(), tau_before_ni.len());
|
||||
for (t, tau) in t.0[0 .. ni].iter().zip(tau_before_ni.iter()) {
|
||||
transcript.push_point(multiexp(&[(*t, self.generators.g()), (*tau, self.generators.h())]));
|
||||
}
|
||||
debug_assert_eq!(t.0[(ni + 1) ..].len(), tau_after_ni.len());
|
||||
for (t, tau) in t.0[(ni + 1) ..].iter().zip(tau_after_ni.iter()) {
|
||||
transcript.push_point(multiexp(&[(*t, self.generators.g()), (*tau, self.generators.h())]));
|
||||
}
|
||||
|
||||
let x: ScalarVector<C::F> = ScalarVector::powers(transcript.challenge(), t.len());
|
||||
|
||||
let poly_eval = |poly: &[ScalarVector<C::F>], x: &ScalarVector<_>| -> ScalarVector<_> {
|
||||
let mut res = ScalarVector::<C::F>::new(poly[0].0.len());
|
||||
for (i, coeff) in poly.iter().enumerate() {
|
||||
res = res + &(coeff.clone() * x[i]);
|
||||
}
|
||||
res
|
||||
};
|
||||
let l = poly_eval(&l, &x);
|
||||
let r = poly_eval(&r, &x);
|
||||
|
||||
let t_caret = l.inner_product(r.0.iter());
|
||||
|
||||
let mut V_weights = ScalarVector::new(self.V.len());
|
||||
for (constraint, z) in self.constraints.iter().zip(&z.0) {
|
||||
// We use `-z`, not `z`, as we write our constraint as `... + WV V = 0` not `= WV V + ..`
|
||||
// This means we need to subtract `WV V` from both sides, which we accomplish here
|
||||
accumulate_vector(&mut V_weights, &constraint.WV, -*z);
|
||||
}
|
||||
|
||||
let tau_x = {
|
||||
let mut tau_x_poly = vec![];
|
||||
tau_x_poly.extend(tau_before_ni);
|
||||
tau_x_poly.push(V_weights.inner_product(witness.v.iter().map(|v| &v.mask)));
|
||||
tau_x_poly.extend(tau_after_ni);
|
||||
|
||||
let mut tau_x = C::F::ZERO;
|
||||
for (i, coeff) in tau_x_poly.into_iter().enumerate() {
|
||||
tau_x += coeff * x[i];
|
||||
}
|
||||
tau_x
|
||||
};
|
||||
|
||||
// Calculate u for the powers of x variable to ilr/io/is
|
||||
let u = {
|
||||
// Calculate the first part of u
|
||||
let mut u = (alpha * x[ilr]) + (beta * x[io]) + (rho * x[is]);
|
||||
|
||||
// Incorporate the commitment masks multiplied by the associated power of x
|
||||
for (i, commitment) in witness.c.iter().enumerate() {
|
||||
let i = i + 1;
|
||||
u += x[i] * commitment.mask;
|
||||
}
|
||||
u
|
||||
};
|
||||
|
||||
// Use the Inner-Product argument to prove for this
|
||||
// P = t_caret * g + l * g_bold + r * (y_inv * h_bold)
|
||||
|
||||
let mut P_terms = Vec::with_capacity(1 + (2 * self.generators.len()));
|
||||
debug_assert_eq!(l.len(), r.len());
|
||||
for (i, (l, r)) in l.0.iter().zip(r.0.iter()).enumerate() {
|
||||
P_terms.push((*l, self.generators.g_bold(i)));
|
||||
P_terms.push((y_inv[i] * r, self.generators.h_bold(i)));
|
||||
}
|
||||
|
||||
// Protocol 1, inlined, since our IpStatement is for Protocol 2
|
||||
transcript.push_scalar(tau_x);
|
||||
transcript.push_scalar(u);
|
||||
transcript.push_scalar(t_caret);
|
||||
let ip_x = transcript.challenge();
|
||||
P_terms.push((ip_x * t_caret, self.generators.g()));
|
||||
IpStatement::new(
|
||||
self.generators,
|
||||
y_inv,
|
||||
ip_x,
|
||||
// Safe since IpStatement isn't a ZK proof
|
||||
P::Prover(multiexp_vartime(&P_terms)),
|
||||
)
|
||||
.unwrap()
|
||||
.prove(transcript, IpWitness::new(l, r).unwrap())
|
||||
.map_err(AcError::Ip)
|
||||
}
|
||||
|
||||
/// Verify a proof for this statement.
|
||||
pub fn verify<R: RngCore + CryptoRng>(
|
||||
self,
|
||||
rng: &mut R,
|
||||
verifier: &mut BatchVerifier<C>,
|
||||
transcript: &mut VerifierTranscript,
|
||||
) -> Result<(), AcError> {
|
||||
let n = self.n();
|
||||
let c = self.c();
|
||||
|
||||
let ni = 2 * (c + 1);
|
||||
|
||||
let ilr = ni / 2;
|
||||
let io = ni;
|
||||
let is = ni + 1;
|
||||
let jlr = ni / 2;
|
||||
|
||||
let l_r_poly_len = 1 + ni + 1;
|
||||
let t_poly_len = (2 * l_r_poly_len) - 1;
|
||||
|
||||
let AI = transcript.read_point::<C>().map_err(|_| AcError::IncompleteProof)?;
|
||||
let AO = transcript.read_point::<C>().map_err(|_| AcError::IncompleteProof)?;
|
||||
let S = transcript.read_point::<C>().map_err(|_| AcError::IncompleteProof)?;
|
||||
let y = transcript.challenge();
|
||||
let z = transcript.challenge();
|
||||
let YzChallenges { y_inv, z } = self.yz_challenges(y, z);
|
||||
|
||||
let mut l_weights = ScalarVector::new(n);
|
||||
let mut r_weights = ScalarVector::new(n);
|
||||
let mut o_weights = ScalarVector::new(n);
|
||||
for (constraint, z) in self.constraints.iter().zip(&z.0) {
|
||||
accumulate_vector(&mut l_weights, &constraint.WL, *z);
|
||||
accumulate_vector(&mut r_weights, &constraint.WR, *z);
|
||||
accumulate_vector(&mut o_weights, &constraint.WO, *z);
|
||||
}
|
||||
let r_weights = r_weights * &y_inv;
|
||||
|
||||
let delta = r_weights.inner_product(l_weights.0.iter());
|
||||
|
||||
let mut T_before_ni = Vec::with_capacity(ni);
|
||||
let mut T_after_ni = Vec::with_capacity(t_poly_len - ni - 1);
|
||||
for _ in 0 .. ni {
|
||||
T_before_ni.push(transcript.read_point::<C>().map_err(|_| AcError::IncompleteProof)?);
|
||||
}
|
||||
for _ in 0 .. (t_poly_len - ni - 1) {
|
||||
T_after_ni.push(transcript.read_point::<C>().map_err(|_| AcError::IncompleteProof)?);
|
||||
}
|
||||
let x: ScalarVector<C::F> = ScalarVector::powers(transcript.challenge(), t_poly_len);
|
||||
|
||||
let tau_x = transcript.read_scalar::<C>().map_err(|_| AcError::IncompleteProof)?;
|
||||
let u = transcript.read_scalar::<C>().map_err(|_| AcError::IncompleteProof)?;
|
||||
let t_caret = transcript.read_scalar::<C>().map_err(|_| AcError::IncompleteProof)?;
|
||||
|
||||
// Lines 88-90, modified per Generalized Bulletproofs as needed w.r.t. t
|
||||
{
|
||||
let verifier_weight = C::F::random(&mut *rng);
|
||||
// lhs of the equation, weighted to enable batch verification
|
||||
verifier.g += t_caret * verifier_weight;
|
||||
verifier.h += tau_x * verifier_weight;
|
||||
|
||||
let mut V_weights = ScalarVector::new(self.V.len());
|
||||
for (constraint, z) in self.constraints.iter().zip(&z.0) {
|
||||
// We use `-z`, not `z`, as we write our constraint as `... + WV V = 0` not `= WV V + ..`
|
||||
// This means we need to subtract `WV V` from both sides, which we accomplish here
|
||||
accumulate_vector(&mut V_weights, &constraint.WV, -*z);
|
||||
}
|
||||
V_weights = V_weights * x[ni];
|
||||
|
||||
// rhs of the equation, negated to cause a sum to zero
|
||||
// `delta - z...`, instead of `delta + z...`, is done for the same reason as in the above WV
|
||||
// matrix transform
|
||||
verifier.g -= verifier_weight *
|
||||
x[ni] *
|
||||
(delta - z.inner_product(self.constraints.iter().map(|constraint| &constraint.c)));
|
||||
for pair in V_weights.0.into_iter().zip(self.V.0) {
|
||||
verifier.additional.push((-verifier_weight * pair.0, pair.1));
|
||||
}
|
||||
for (i, T) in T_before_ni.into_iter().enumerate() {
|
||||
verifier.additional.push((-verifier_weight * x[i], T));
|
||||
}
|
||||
for (i, T) in T_after_ni.into_iter().enumerate() {
|
||||
verifier.additional.push((-verifier_weight * x[ni + 1 + i], T));
|
||||
}
|
||||
}
|
||||
|
||||
let verifier_weight = C::F::random(&mut *rng);
|
||||
// Multiply `x` by `verifier_weight` as this effects `verifier_weight` onto most scalars and
|
||||
// saves a notable amount of operations
|
||||
let x = x * verifier_weight;
|
||||
|
||||
// This following block effectively calculates P, within the multiexp
|
||||
{
|
||||
verifier.additional.push((x[ilr], AI));
|
||||
verifier.additional.push((x[io], AO));
|
||||
// h' ** y is equivalent to h as h' is h ** y_inv
|
||||
let mut log2_n = 0;
|
||||
while (1 << log2_n) != n {
|
||||
log2_n += 1;
|
||||
}
|
||||
verifier.h_sum[log2_n] -= verifier_weight;
|
||||
verifier.additional.push((x[is], S));
|
||||
|
||||
// Lines 85-87 calculate WL, WR, WO
|
||||
// We preserve them in terms of g_bold and h_bold for a more efficient multiexp
|
||||
let mut h_bold_scalars = l_weights * x[jlr];
|
||||
for (i, wr) in (r_weights * x[jlr]).0.into_iter().enumerate() {
|
||||
verifier.g_bold[i] += wr;
|
||||
}
|
||||
// WO is weighted by x**jo where jo == 0, hence why we can ignore the x term
|
||||
h_bold_scalars = h_bold_scalars + &(o_weights * verifier_weight);
|
||||
|
||||
let mut cg_weights = Vec::with_capacity(self.C.len());
|
||||
let mut ch_weights = Vec::with_capacity(self.C.len());
|
||||
for i in 0 .. self.C.len() {
|
||||
let mut cg = ScalarVector::new(n);
|
||||
let mut ch = ScalarVector::new(n);
|
||||
for (constraint, z) in self.constraints.iter().zip(&z.0) {
|
||||
if let Some(WCG) = constraint.WCG.get(i) {
|
||||
accumulate_vector(&mut cg, WCG, *z);
|
||||
}
|
||||
if let Some(WCH) = constraint.WCH.get(i) {
|
||||
accumulate_vector(&mut ch, WCH, *z);
|
||||
}
|
||||
}
|
||||
cg_weights.push(cg);
|
||||
ch_weights.push(ch);
|
||||
}
|
||||
|
||||
// Push the terms for C, which increment from 0, and the terms for WC, which decrement from
|
||||
// n'
|
||||
for (i, (C, (WCG, WCH))) in
|
||||
self.C.0.into_iter().zip(cg_weights.into_iter().zip(ch_weights)).enumerate()
|
||||
{
|
||||
let i = i + 1;
|
||||
let j = ni - i;
|
||||
verifier.additional.push((x[i], C));
|
||||
h_bold_scalars = h_bold_scalars + &(WCG * x[j]);
|
||||
for (i, scalar) in (WCH * &y_inv * x[j]).0.into_iter().enumerate() {
|
||||
verifier.g_bold[i] += scalar;
|
||||
}
|
||||
}
|
||||
|
||||
// All terms for h_bold here have actually been for h_bold', h_bold * y_inv
|
||||
h_bold_scalars = h_bold_scalars * &y_inv;
|
||||
for (i, scalar) in h_bold_scalars.0.into_iter().enumerate() {
|
||||
verifier.h_bold[i] += scalar;
|
||||
}
|
||||
|
||||
// Remove u * h from P
|
||||
verifier.h -= verifier_weight * u;
|
||||
}
|
||||
|
||||
// Prove for lines 88, 92 with an Inner-Product statement
|
||||
// This inlines Protocol 1, as our IpStatement implements Protocol 2
|
||||
let ip_x = transcript.challenge();
|
||||
// P is amended with this additional term
|
||||
verifier.g += verifier_weight * ip_x * t_caret;
|
||||
IpStatement::new(self.generators, y_inv, ip_x, P::Verifier { verifier_weight })
|
||||
.unwrap()
|
||||
.verify(verifier, transcript)
|
||||
.map_err(AcError::Ip)?;
|
||||
|
||||
Ok(())
|
||||
}
|
||||
}
|
||||
360
crypto/evrf/generalized-bulletproofs/src/inner_product.rs
Normal file
360
crypto/evrf/generalized-bulletproofs/src/inner_product.rs
Normal file
@@ -0,0 +1,360 @@
|
||||
use multiexp::multiexp_vartime;
|
||||
use ciphersuite::{group::ff::Field, Ciphersuite};
|
||||
|
||||
#[rustfmt::skip]
|
||||
use crate::{ScalarVector, PointVector, ProofGenerators, BatchVerifier, transcript::*, padded_pow_of_2};
|
||||
|
||||
/// An error from proving/verifying Inner-Product statements.
|
||||
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
|
||||
pub enum IpError {
|
||||
/// An incorrect amount of generators was provided.
|
||||
IncorrectAmountOfGenerators,
|
||||
/// The witness was inconsistent to the statement.
|
||||
///
|
||||
/// Sanity checks on the witness are always performed. If the library is compiled with debug
|
||||
/// assertions on, whether or not this witness actually opens `P` is checked.
|
||||
InconsistentWitness,
|
||||
/// The proof wasn't complete and the necessary values could not be read from the transcript.
|
||||
IncompleteProof,
|
||||
}
|
||||
|
||||
#[derive(Clone, PartialEq, Eq, Debug)]
|
||||
pub(crate) enum P<C: Ciphersuite> {
|
||||
Verifier { verifier_weight: C::F },
|
||||
Prover(C::G),
|
||||
}
|
||||
|
||||
/// The Bulletproofs Inner-Product statement.
|
||||
///
|
||||
/// This is for usage with Protocol 2 from the Bulletproofs paper.
|
||||
#[derive(Clone, Debug)]
|
||||
pub(crate) struct IpStatement<'a, C: Ciphersuite> {
|
||||
generators: ProofGenerators<'a, C>,
|
||||
// Weights for h_bold
|
||||
h_bold_weights: ScalarVector<C::F>,
|
||||
// u as the discrete logarithm of G
|
||||
u: C::F,
|
||||
// P
|
||||
P: P<C>,
|
||||
}
|
||||
|
||||
/// The witness for the Bulletproofs Inner-Product statement.
|
||||
#[derive(Clone, Debug)]
|
||||
pub(crate) struct IpWitness<C: Ciphersuite> {
|
||||
// a
|
||||
a: ScalarVector<C::F>,
|
||||
// b
|
||||
b: ScalarVector<C::F>,
|
||||
}
|
||||
|
||||
impl<C: Ciphersuite> IpWitness<C> {
|
||||
/// Construct a new witness for an Inner-Product statement.
|
||||
///
|
||||
/// If the witness is less than a power of two, it is padded to the nearest power of two.
|
||||
///
|
||||
/// This functions return None if the lengths of a, b are mismatched or either are empty.
|
||||
pub(crate) fn new(mut a: ScalarVector<C::F>, mut b: ScalarVector<C::F>) -> Option<Self> {
|
||||
if a.0.is_empty() || (a.len() != b.len()) {
|
||||
None?;
|
||||
}
|
||||
|
||||
// Pad to the nearest power of 2
|
||||
let missing = padded_pow_of_2(a.len()) - a.len();
|
||||
a.0.reserve(missing);
|
||||
b.0.reserve(missing);
|
||||
for _ in 0 .. missing {
|
||||
a.0.push(C::F::ZERO);
|
||||
b.0.push(C::F::ZERO);
|
||||
}
|
||||
|
||||
Some(Self { a, b })
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, C: Ciphersuite> IpStatement<'a, C> {
|
||||
/// Create a new Inner-Product statement.
|
||||
///
|
||||
/// This does not perform any transcripting of any variables within this statement. They must be
|
||||
/// deterministic to the existing transcript.
|
||||
pub(crate) fn new(
|
||||
generators: ProofGenerators<'a, C>,
|
||||
h_bold_weights: ScalarVector<C::F>,
|
||||
u: C::F,
|
||||
P: P<C>,
|
||||
) -> Result<Self, IpError> {
|
||||
if generators.h_bold_slice().len() != h_bold_weights.len() {
|
||||
Err(IpError::IncorrectAmountOfGenerators)?
|
||||
}
|
||||
Ok(Self { generators, h_bold_weights, u, P })
|
||||
}
|
||||
|
||||
/// Prove for this Inner-Product statement.
|
||||
///
|
||||
/// Returns an error if this statement couldn't be proven for (such as if the witness isn't
|
||||
/// consistent).
|
||||
pub(crate) fn prove(
|
||||
self,
|
||||
transcript: &mut Transcript,
|
||||
witness: IpWitness<C>,
|
||||
) -> Result<(), IpError> {
|
||||
let (mut g_bold, mut h_bold, u, mut P, mut a, mut b) = {
|
||||
let IpStatement { generators, h_bold_weights, u, P } = self;
|
||||
let u = generators.g() * u;
|
||||
|
||||
// Ensure we have the exact amount of generators
|
||||
if generators.g_bold_slice().len() != witness.a.len() {
|
||||
Err(IpError::IncorrectAmountOfGenerators)?;
|
||||
}
|
||||
// Acquire a local copy of the generators
|
||||
let g_bold = PointVector::<C>(generators.g_bold_slice().to_vec());
|
||||
let h_bold = PointVector::<C>(generators.h_bold_slice().to_vec()).mul_vec(&h_bold_weights);
|
||||
|
||||
let IpWitness { a, b } = witness;
|
||||
|
||||
let P = match P {
|
||||
P::Prover(point) => point,
|
||||
P::Verifier { .. } => {
|
||||
panic!("prove called with a P specification which was for the verifier")
|
||||
}
|
||||
};
|
||||
|
||||
// Ensure this witness actually opens this statement
|
||||
#[cfg(debug_assertions)]
|
||||
{
|
||||
let ag = a.0.iter().cloned().zip(g_bold.0.iter().cloned());
|
||||
let bh = b.0.iter().cloned().zip(h_bold.0.iter().cloned());
|
||||
let cu = core::iter::once((a.inner_product(b.0.iter()), u));
|
||||
if P != multiexp_vartime(&ag.chain(bh).chain(cu).collect::<Vec<_>>()) {
|
||||
Err(IpError::InconsistentWitness)?;
|
||||
}
|
||||
}
|
||||
|
||||
(g_bold, h_bold, u, P, a, b)
|
||||
};
|
||||
|
||||
// `else: (n > 1)` case, lines 18-35 of the Bulletproofs paper
|
||||
// This interprets `g_bold.len()` as `n`
|
||||
while g_bold.len() > 1 {
|
||||
// Split a, b, g_bold, h_bold as needed for lines 20-24
|
||||
let (a1, a2) = a.clone().split();
|
||||
let (b1, b2) = b.clone().split();
|
||||
|
||||
let (g_bold1, g_bold2) = g_bold.split();
|
||||
let (h_bold1, h_bold2) = h_bold.split();
|
||||
|
||||
let n_hat = g_bold1.len();
|
||||
|
||||
// Sanity
|
||||
debug_assert_eq!(a1.len(), n_hat);
|
||||
debug_assert_eq!(a2.len(), n_hat);
|
||||
debug_assert_eq!(b1.len(), n_hat);
|
||||
debug_assert_eq!(b2.len(), n_hat);
|
||||
debug_assert_eq!(g_bold1.len(), n_hat);
|
||||
debug_assert_eq!(g_bold2.len(), n_hat);
|
||||
debug_assert_eq!(h_bold1.len(), n_hat);
|
||||
debug_assert_eq!(h_bold2.len(), n_hat);
|
||||
|
||||
// cl, cr, lines 21-22
|
||||
let cl = a1.inner_product(b2.0.iter());
|
||||
let cr = a2.inner_product(b1.0.iter());
|
||||
|
||||
let L = {
|
||||
let mut L_terms = Vec::with_capacity(1 + (2 * g_bold1.len()));
|
||||
for (a, g) in a1.0.iter().zip(g_bold2.0.iter()) {
|
||||
L_terms.push((*a, *g));
|
||||
}
|
||||
for (b, h) in b2.0.iter().zip(h_bold1.0.iter()) {
|
||||
L_terms.push((*b, *h));
|
||||
}
|
||||
L_terms.push((cl, u));
|
||||
// Uses vartime since this isn't a ZK proof
|
||||
multiexp_vartime(&L_terms)
|
||||
};
|
||||
|
||||
let R = {
|
||||
let mut R_terms = Vec::with_capacity(1 + (2 * g_bold1.len()));
|
||||
for (a, g) in a2.0.iter().zip(g_bold1.0.iter()) {
|
||||
R_terms.push((*a, *g));
|
||||
}
|
||||
for (b, h) in b1.0.iter().zip(h_bold2.0.iter()) {
|
||||
R_terms.push((*b, *h));
|
||||
}
|
||||
R_terms.push((cr, u));
|
||||
multiexp_vartime(&R_terms)
|
||||
};
|
||||
|
||||
// Now that we've calculate L, R, transcript them to receive x (26-27)
|
||||
transcript.push_point(L);
|
||||
transcript.push_point(R);
|
||||
let x: C::F = transcript.challenge();
|
||||
let x_inv = x.invert().unwrap();
|
||||
|
||||
// The prover and verifier now calculate the following (28-31)
|
||||
g_bold = PointVector(Vec::with_capacity(g_bold1.len()));
|
||||
for (a, b) in g_bold1.0.into_iter().zip(g_bold2.0.into_iter()) {
|
||||
g_bold.0.push(multiexp_vartime(&[(x_inv, a), (x, b)]));
|
||||
}
|
||||
h_bold = PointVector(Vec::with_capacity(h_bold1.len()));
|
||||
for (a, b) in h_bold1.0.into_iter().zip(h_bold2.0.into_iter()) {
|
||||
h_bold.0.push(multiexp_vartime(&[(x, a), (x_inv, b)]));
|
||||
}
|
||||
P = (L * (x * x)) + P + (R * (x_inv * x_inv));
|
||||
|
||||
// 32-34
|
||||
a = (a1 * x) + &(a2 * x_inv);
|
||||
b = (b1 * x_inv) + &(b2 * x);
|
||||
}
|
||||
|
||||
// `if n = 1` case from line 14-17
|
||||
|
||||
// Sanity
|
||||
debug_assert_eq!(g_bold.len(), 1);
|
||||
debug_assert_eq!(h_bold.len(), 1);
|
||||
debug_assert_eq!(a.len(), 1);
|
||||
debug_assert_eq!(b.len(), 1);
|
||||
|
||||
// We simply send a/b
|
||||
transcript.push_scalar(a[0]);
|
||||
transcript.push_scalar(b[0]);
|
||||
Ok(())
|
||||
}
|
||||
|
||||
/*
|
||||
This has room for optimization worth investigating further. It currently takes
|
||||
an iterative approach. It can be optimized further via divide and conquer.
|
||||
|
||||
Assume there are 4 challenges.
|
||||
|
||||
Iterative approach (current):
|
||||
1. Do the optimal multiplications across challenge column 0 and 1.
|
||||
2. Do the optimal multiplications across that result and column 2.
|
||||
3. Do the optimal multiplications across that result and column 3.
|
||||
|
||||
Divide and conquer (worth investigating further):
|
||||
1. Do the optimal multiplications across challenge column 0 and 1.
|
||||
2. Do the optimal multiplications across challenge column 2 and 3.
|
||||
3. Multiply both results together.
|
||||
|
||||
When there are 4 challenges (n=16), the iterative approach does 28 multiplications
|
||||
versus divide and conquer's 24.
|
||||
*/
|
||||
fn challenge_products(challenges: &[(C::F, C::F)]) -> Vec<C::F> {
|
||||
let mut products = vec![C::F::ONE; 1 << challenges.len()];
|
||||
|
||||
if !challenges.is_empty() {
|
||||
products[0] = challenges[0].1;
|
||||
products[1] = challenges[0].0;
|
||||
|
||||
for (j, challenge) in challenges.iter().enumerate().skip(1) {
|
||||
let mut slots = (1 << (j + 1)) - 1;
|
||||
while slots > 0 {
|
||||
products[slots] = products[slots / 2] * challenge.0;
|
||||
products[slots - 1] = products[slots / 2] * challenge.1;
|
||||
|
||||
slots = slots.saturating_sub(2);
|
||||
}
|
||||
}
|
||||
|
||||
// Sanity check since if the above failed to populate, it'd be critical
|
||||
for product in &products {
|
||||
debug_assert!(!bool::from(product.is_zero()));
|
||||
}
|
||||
}
|
||||
|
||||
products
|
||||
}
|
||||
|
||||
/// Queue an Inner-Product proof for batch verification.
|
||||
///
|
||||
/// This will return Err if there is an error. This will return Ok if the proof was successfully
|
||||
/// queued for batch verification. The caller is required to verify the batch in order to ensure
|
||||
/// the proof is actually correct.
|
||||
pub(crate) fn verify(
|
||||
self,
|
||||
verifier: &mut BatchVerifier<C>,
|
||||
transcript: &mut VerifierTranscript,
|
||||
) -> Result<(), IpError> {
|
||||
let IpStatement { generators, h_bold_weights, u, P } = self;
|
||||
|
||||
// Calculate the discrete log w.r.t. 2 for the amount of generators present
|
||||
let mut lr_len = 0;
|
||||
while (1 << lr_len) < generators.g_bold_slice().len() {
|
||||
lr_len += 1;
|
||||
}
|
||||
|
||||
let weight = match P {
|
||||
P::Prover(_) => panic!("prove called with a P specification which was for the prover"),
|
||||
P::Verifier { verifier_weight } => verifier_weight,
|
||||
};
|
||||
|
||||
// Again, we start with the `else: (n > 1)` case
|
||||
|
||||
// We need x, x_inv per lines 25-27 for lines 28-31
|
||||
let mut L = Vec::with_capacity(lr_len);
|
||||
let mut R = Vec::with_capacity(lr_len);
|
||||
let mut xs: Vec<C::F> = Vec::with_capacity(lr_len);
|
||||
for _ in 0 .. lr_len {
|
||||
L.push(transcript.read_point::<C>().map_err(|_| IpError::IncompleteProof)?);
|
||||
R.push(transcript.read_point::<C>().map_err(|_| IpError::IncompleteProof)?);
|
||||
xs.push(transcript.challenge());
|
||||
}
|
||||
|
||||
// We calculate their inverse in batch
|
||||
let mut x_invs = xs.clone();
|
||||
{
|
||||
let mut scratch = vec![C::F::ZERO; x_invs.len()];
|
||||
ciphersuite::group::ff::BatchInverter::invert_with_external_scratch(
|
||||
&mut x_invs,
|
||||
&mut scratch,
|
||||
);
|
||||
}
|
||||
|
||||
// Now, with x and x_inv, we need to calculate g_bold', h_bold', P'
|
||||
//
|
||||
// For the sake of performance, we solely want to calculate all of these in terms of scalings
|
||||
// for g_bold, h_bold, P, and don't want to actually perform intermediary scalings of the
|
||||
// points
|
||||
//
|
||||
// L and R are easy, as it's simply x**2, x**-2
|
||||
//
|
||||
// For the series of g_bold, h_bold, we use the `challenge_products` function
|
||||
// For how that works, please see its own documentation
|
||||
let product_cache = {
|
||||
let mut challenges = Vec::with_capacity(lr_len);
|
||||
|
||||
let x_iter = xs.into_iter().zip(x_invs);
|
||||
let lr_iter = L.into_iter().zip(R);
|
||||
for ((x, x_inv), (L, R)) in x_iter.zip(lr_iter) {
|
||||
challenges.push((x, x_inv));
|
||||
verifier.additional.push((weight * x.square(), L));
|
||||
verifier.additional.push((weight * x_inv.square(), R));
|
||||
}
|
||||
|
||||
Self::challenge_products(&challenges)
|
||||
};
|
||||
|
||||
// And now for the `if n = 1` case
|
||||
let a = transcript.read_scalar::<C>().map_err(|_| IpError::IncompleteProof)?;
|
||||
let b = transcript.read_scalar::<C>().map_err(|_| IpError::IncompleteProof)?;
|
||||
let c = a * b;
|
||||
|
||||
// The multiexp of these terms equate to the final permutation of P
|
||||
// We now add terms for a * g_bold' + b * h_bold' b + c * u, with the scalars negative such
|
||||
// that the terms sum to 0 for an honest prover
|
||||
|
||||
// The g_bold * a term case from line 16
|
||||
#[allow(clippy::needless_range_loop)]
|
||||
for i in 0 .. generators.g_bold_slice().len() {
|
||||
verifier.g_bold[i] -= weight * product_cache[i] * a;
|
||||
}
|
||||
// The h_bold * b term case from line 16
|
||||
for i in 0 .. generators.h_bold_slice().len() {
|
||||
verifier.h_bold[i] -=
|
||||
weight * product_cache[product_cache.len() - 1 - i] * b * h_bold_weights[i];
|
||||
}
|
||||
// The c * u term case from line 16
|
||||
verifier.g -= weight * c * u;
|
||||
|
||||
Ok(())
|
||||
}
|
||||
}
|
||||
328
crypto/evrf/generalized-bulletproofs/src/lib.rs
Normal file
328
crypto/evrf/generalized-bulletproofs/src/lib.rs
Normal file
@@ -0,0 +1,328 @@
|
||||
#![cfg_attr(docsrs, feature(doc_auto_cfg))]
|
||||
#![doc = include_str!("../README.md")]
|
||||
#![deny(missing_docs)]
|
||||
#![allow(non_snake_case)]
|
||||
|
||||
use core::fmt;
|
||||
use std::collections::HashSet;
|
||||
|
||||
use zeroize::Zeroize;
|
||||
|
||||
use multiexp::{multiexp, multiexp_vartime};
|
||||
use ciphersuite::{
|
||||
group::{ff::Field, Group, GroupEncoding},
|
||||
Ciphersuite,
|
||||
};
|
||||
|
||||
mod scalar_vector;
|
||||
pub use scalar_vector::ScalarVector;
|
||||
mod point_vector;
|
||||
pub use point_vector::PointVector;
|
||||
|
||||
/// The transcript formats.
|
||||
pub mod transcript;
|
||||
|
||||
pub(crate) mod inner_product;
|
||||
|
||||
pub(crate) mod lincomb;
|
||||
|
||||
/// The arithmetic circuit proof.
|
||||
pub mod arithmetic_circuit_proof;
|
||||
|
||||
/// Functionlity useful when testing.
|
||||
#[cfg(any(test, feature = "tests"))]
|
||||
pub mod tests;
|
||||
|
||||
/// Calculate the nearest power of two greater than or equivalent to the argument.
|
||||
pub(crate) fn padded_pow_of_2(i: usize) -> usize {
|
||||
let mut next_pow_of_2 = 1;
|
||||
while next_pow_of_2 < i {
|
||||
next_pow_of_2 <<= 1;
|
||||
}
|
||||
next_pow_of_2
|
||||
}
|
||||
|
||||
/// An error from working with generators.
|
||||
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
|
||||
pub enum GeneratorsError {
|
||||
/// The provided list of generators for `g` (bold) was empty.
|
||||
GBoldEmpty,
|
||||
/// The provided list of generators for `h` (bold) did not match `g` (bold) in length.
|
||||
DifferingGhBoldLengths,
|
||||
/// The amount of provided generators were not a power of two.
|
||||
NotPowerOfTwo,
|
||||
/// A generator was used multiple times.
|
||||
DuplicatedGenerator,
|
||||
}
|
||||
|
||||
/// A full set of generators.
|
||||
#[derive(Clone)]
|
||||
pub struct Generators<C: Ciphersuite> {
|
||||
g: C::G,
|
||||
h: C::G,
|
||||
|
||||
g_bold: Vec<C::G>,
|
||||
h_bold: Vec<C::G>,
|
||||
h_sum: Vec<C::G>,
|
||||
}
|
||||
|
||||
/// A batch verifier of proofs.
|
||||
#[must_use]
|
||||
#[derive(Clone)]
|
||||
pub struct BatchVerifier<C: Ciphersuite> {
|
||||
g: C::F,
|
||||
h: C::F,
|
||||
|
||||
g_bold: Vec<C::F>,
|
||||
h_bold: Vec<C::F>,
|
||||
h_sum: Vec<C::F>,
|
||||
|
||||
additional: Vec<(C::F, C::G)>,
|
||||
}
|
||||
|
||||
impl<C: Ciphersuite> fmt::Debug for Generators<C> {
|
||||
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
let g = self.g.to_bytes();
|
||||
let g: &[u8] = g.as_ref();
|
||||
|
||||
let h = self.h.to_bytes();
|
||||
let h: &[u8] = h.as_ref();
|
||||
|
||||
fmt.debug_struct("Generators").field("g", &g).field("h", &h).finish_non_exhaustive()
|
||||
}
|
||||
}
|
||||
|
||||
/// The generators for a specific proof.
|
||||
///
|
||||
/// This potentially have been reduced in size from the original set of generators, as beneficial
|
||||
/// to performance.
|
||||
#[derive(Copy, Clone)]
|
||||
pub struct ProofGenerators<'a, C: Ciphersuite> {
|
||||
g: &'a C::G,
|
||||
h: &'a C::G,
|
||||
|
||||
g_bold: &'a [C::G],
|
||||
h_bold: &'a [C::G],
|
||||
}
|
||||
|
||||
impl<C: Ciphersuite> fmt::Debug for ProofGenerators<'_, C> {
|
||||
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
|
||||
let g = self.g.to_bytes();
|
||||
let g: &[u8] = g.as_ref();
|
||||
|
||||
let h = self.h.to_bytes();
|
||||
let h: &[u8] = h.as_ref();
|
||||
|
||||
fmt.debug_struct("ProofGenerators").field("g", &g).field("h", &h).finish_non_exhaustive()
|
||||
}
|
||||
}
|
||||
|
||||
impl<C: Ciphersuite> Generators<C> {
|
||||
/// Construct an instance of Generators for usage with Bulletproofs.
|
||||
pub fn new(
|
||||
g: C::G,
|
||||
h: C::G,
|
||||
g_bold: Vec<C::G>,
|
||||
h_bold: Vec<C::G>,
|
||||
) -> Result<Self, GeneratorsError> {
|
||||
if g_bold.is_empty() {
|
||||
Err(GeneratorsError::GBoldEmpty)?;
|
||||
}
|
||||
if g_bold.len() != h_bold.len() {
|
||||
Err(GeneratorsError::DifferingGhBoldLengths)?;
|
||||
}
|
||||
if padded_pow_of_2(g_bold.len()) != g_bold.len() {
|
||||
Err(GeneratorsError::NotPowerOfTwo)?;
|
||||
}
|
||||
|
||||
let mut set = HashSet::new();
|
||||
let mut add_generator = |generator: &C::G| {
|
||||
assert!(!bool::from(generator.is_identity()));
|
||||
let bytes = generator.to_bytes();
|
||||
!set.insert(bytes.as_ref().to_vec())
|
||||
};
|
||||
|
||||
assert!(!add_generator(&g), "g was prior present in empty set");
|
||||
if add_generator(&h) {
|
||||
Err(GeneratorsError::DuplicatedGenerator)?;
|
||||
}
|
||||
for g in &g_bold {
|
||||
if add_generator(g) {
|
||||
Err(GeneratorsError::DuplicatedGenerator)?;
|
||||
}
|
||||
}
|
||||
for h in &h_bold {
|
||||
if add_generator(h) {
|
||||
Err(GeneratorsError::DuplicatedGenerator)?;
|
||||
}
|
||||
}
|
||||
|
||||
let mut running_h_sum = C::G::identity();
|
||||
let mut h_sum = vec![];
|
||||
let mut next_pow_of_2 = 1;
|
||||
for (i, h) in h_bold.iter().enumerate() {
|
||||
running_h_sum += h;
|
||||
if (i + 1) == next_pow_of_2 {
|
||||
h_sum.push(running_h_sum);
|
||||
next_pow_of_2 *= 2;
|
||||
}
|
||||
}
|
||||
|
||||
Ok(Generators { g, h, g_bold, h_bold, h_sum })
|
||||
}
|
||||
|
||||
/// Create a BatchVerifier for proofs which use these generators.
|
||||
pub fn batch_verifier(&self) -> BatchVerifier<C> {
|
||||
BatchVerifier {
|
||||
g: C::F::ZERO,
|
||||
h: C::F::ZERO,
|
||||
|
||||
g_bold: vec![C::F::ZERO; self.g_bold.len()],
|
||||
h_bold: vec![C::F::ZERO; self.h_bold.len()],
|
||||
h_sum: vec![C::F::ZERO; self.h_sum.len()],
|
||||
|
||||
additional: Vec::with_capacity(128),
|
||||
}
|
||||
}
|
||||
|
||||
/// Verify all proofs queued for batch verification in this BatchVerifier.
|
||||
#[must_use]
|
||||
pub fn verify(&self, verifier: BatchVerifier<C>) -> bool {
|
||||
multiexp_vartime(
|
||||
&[(verifier.g, self.g), (verifier.h, self.h)]
|
||||
.into_iter()
|
||||
.chain(verifier.g_bold.into_iter().zip(self.g_bold.iter().cloned()))
|
||||
.chain(verifier.h_bold.into_iter().zip(self.h_bold.iter().cloned()))
|
||||
.chain(verifier.h_sum.into_iter().zip(self.h_sum.iter().cloned()))
|
||||
.chain(verifier.additional)
|
||||
.collect::<Vec<_>>(),
|
||||
)
|
||||
.is_identity()
|
||||
.into()
|
||||
}
|
||||
|
||||
/// The `g` generator.
|
||||
pub fn g(&self) -> C::G {
|
||||
self.g
|
||||
}
|
||||
|
||||
/// The `h` generator.
|
||||
pub fn h(&self) -> C::G {
|
||||
self.h
|
||||
}
|
||||
|
||||
/// A slice to view the `g` (bold) generators.
|
||||
pub fn g_bold_slice(&self) -> &[C::G] {
|
||||
&self.g_bold
|
||||
}
|
||||
|
||||
/// A slice to view the `h` (bold) generators.
|
||||
pub fn h_bold_slice(&self) -> &[C::G] {
|
||||
&self.h_bold
|
||||
}
|
||||
|
||||
/// Reduce a set of generators to the quantity necessary to support a certain amount of
|
||||
/// in-circuit multiplications/terms in a Pedersen vector commitment.
|
||||
///
|
||||
/// Returns None if reducing to 0 or if the generators reduced are insufficient to provide this
|
||||
/// many generators.
|
||||
pub fn reduce(&self, generators: usize) -> Option<ProofGenerators<'_, C>> {
|
||||
if generators == 0 {
|
||||
None?;
|
||||
}
|
||||
|
||||
// Round to the nearest power of 2
|
||||
let generators = padded_pow_of_2(generators);
|
||||
if generators > self.g_bold.len() {
|
||||
None?;
|
||||
}
|
||||
|
||||
Some(ProofGenerators {
|
||||
g: &self.g,
|
||||
h: &self.h,
|
||||
|
||||
g_bold: &self.g_bold[.. generators],
|
||||
h_bold: &self.h_bold[.. generators],
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, C: Ciphersuite> ProofGenerators<'a, C> {
|
||||
pub(crate) fn len(&self) -> usize {
|
||||
self.g_bold.len()
|
||||
}
|
||||
|
||||
pub(crate) fn g(&self) -> C::G {
|
||||
*self.g
|
||||
}
|
||||
|
||||
pub(crate) fn h(&self) -> C::G {
|
||||
*self.h
|
||||
}
|
||||
|
||||
pub(crate) fn g_bold(&self, i: usize) -> C::G {
|
||||
self.g_bold[i]
|
||||
}
|
||||
|
||||
pub(crate) fn h_bold(&self, i: usize) -> C::G {
|
||||
self.h_bold[i]
|
||||
}
|
||||
|
||||
pub(crate) fn g_bold_slice(&self) -> &[C::G] {
|
||||
self.g_bold
|
||||
}
|
||||
|
||||
pub(crate) fn h_bold_slice(&self) -> &[C::G] {
|
||||
self.h_bold
|
||||
}
|
||||
}
|
||||
|
||||
/// The opening of a Pedersen commitment.
|
||||
#[derive(Clone, Copy, PartialEq, Eq, Debug, Zeroize)]
|
||||
pub struct PedersenCommitment<C: Ciphersuite> {
|
||||
/// The value committed to.
|
||||
pub value: C::F,
|
||||
/// The mask blinding the value committed to.
|
||||
pub mask: C::F,
|
||||
}
|
||||
|
||||
impl<C: Ciphersuite> PedersenCommitment<C> {
|
||||
/// Commit to this value, yielding the Pedersen commitment.
|
||||
pub fn commit(&self, g: C::G, h: C::G) -> C::G {
|
||||
multiexp(&[(self.value, g), (self.mask, h)])
|
||||
}
|
||||
}
|
||||
|
||||
/// The opening of a Pedersen vector commitment.
|
||||
#[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
|
||||
pub struct PedersenVectorCommitment<C: Ciphersuite> {
|
||||
/// The values committed to across the `g` (bold) generators.
|
||||
pub g_values: ScalarVector<C::F>,
|
||||
/// The values committed to across the `h` (bold) generators.
|
||||
pub h_values: ScalarVector<C::F>,
|
||||
/// The mask blinding the values committed to.
|
||||
pub mask: C::F,
|
||||
}
|
||||
|
||||
impl<C: Ciphersuite> PedersenVectorCommitment<C> {
|
||||
/// Commit to the vectors of values.
|
||||
///
|
||||
/// This function returns None if the amount of generators is less than the amount of values
|
||||
/// within the relevant vector.
|
||||
pub fn commit(&self, g_bold: &[C::G], h_bold: &[C::G], h: C::G) -> Option<C::G> {
|
||||
if (g_bold.len() < self.g_values.len()) || (h_bold.len() < self.h_values.len()) {
|
||||
None?;
|
||||
};
|
||||
|
||||
let mut terms = vec![(self.mask, h)];
|
||||
for pair in self.g_values.0.iter().cloned().zip(g_bold.iter().cloned()) {
|
||||
terms.push(pair);
|
||||
}
|
||||
for pair in self.h_values.0.iter().cloned().zip(h_bold.iter().cloned()) {
|
||||
terms.push(pair);
|
||||
}
|
||||
let res = multiexp(&terms);
|
||||
terms.zeroize();
|
||||
Some(res)
|
||||
}
|
||||
}
|
||||
265
crypto/evrf/generalized-bulletproofs/src/lincomb.rs
Normal file
265
crypto/evrf/generalized-bulletproofs/src/lincomb.rs
Normal file
@@ -0,0 +1,265 @@
|
||||
use core::ops::{Add, Sub, Mul};
|
||||
|
||||
use zeroize::Zeroize;
|
||||
|
||||
use ciphersuite::group::ff::PrimeField;
|
||||
|
||||
use crate::ScalarVector;
|
||||
|
||||
/// A reference to a variable usable within linear combinations.
|
||||
#[derive(Clone, Copy, PartialEq, Eq, Debug)]
|
||||
#[allow(non_camel_case_types)]
|
||||
pub enum Variable {
|
||||
/// A variable within the left vector of vectors multiplied against each other.
|
||||
aL(usize),
|
||||
/// A variable within the right vector of vectors multiplied against each other.
|
||||
aR(usize),
|
||||
/// A variable within the output vector of the left vector multiplied by the right vector.
|
||||
aO(usize),
|
||||
/// A variable within a Pedersen vector commitment, committed to with a generator from `g` (bold).
|
||||
CG {
|
||||
/// The commitment being indexed.
|
||||
commitment: usize,
|
||||
/// The index of the variable.
|
||||
index: usize,
|
||||
},
|
||||
/// A variable within a Pedersen vector commitment, committed to with a generator from `h` (bold).
|
||||
CH {
|
||||
/// The commitment being indexed.
|
||||
commitment: usize,
|
||||
/// The index of the variable.
|
||||
index: usize,
|
||||
},
|
||||
/// A variable within a Pedersen commitment.
|
||||
V(usize),
|
||||
}
|
||||
|
||||
// Does a NOP as there shouldn't be anything critical here
|
||||
impl Zeroize for Variable {
|
||||
fn zeroize(&mut self) {}
|
||||
}
|
||||
|
||||
/// A linear combination.
|
||||
///
|
||||
/// Specifically, `WL aL + WR aR + WO aO + WCG C_G + WCH C_H + WV V + c`.
|
||||
#[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
|
||||
#[must_use]
|
||||
pub struct LinComb<F: PrimeField> {
|
||||
pub(crate) highest_a_index: Option<usize>,
|
||||
pub(crate) highest_c_index: Option<usize>,
|
||||
pub(crate) highest_v_index: Option<usize>,
|
||||
|
||||
// Sparse representation of WL/WR/WO
|
||||
pub(crate) WL: Vec<(usize, F)>,
|
||||
pub(crate) WR: Vec<(usize, F)>,
|
||||
pub(crate) WO: Vec<(usize, F)>,
|
||||
// Sparse representation once within a commitment
|
||||
pub(crate) WCG: Vec<Vec<(usize, F)>>,
|
||||
pub(crate) WCH: Vec<Vec<(usize, F)>>,
|
||||
// Sparse representation of WV
|
||||
pub(crate) WV: Vec<(usize, F)>,
|
||||
pub(crate) c: F,
|
||||
}
|
||||
|
||||
impl<F: PrimeField> From<Variable> for LinComb<F> {
|
||||
fn from(constrainable: Variable) -> LinComb<F> {
|
||||
LinComb::empty().term(F::ONE, constrainable)
|
||||
}
|
||||
}
|
||||
|
||||
impl<F: PrimeField> Add<&LinComb<F>> for LinComb<F> {
|
||||
type Output = Self;
|
||||
|
||||
fn add(mut self, constraint: &Self) -> Self {
|
||||
self.highest_a_index = self.highest_a_index.max(constraint.highest_a_index);
|
||||
self.highest_c_index = self.highest_c_index.max(constraint.highest_c_index);
|
||||
self.highest_v_index = self.highest_v_index.max(constraint.highest_v_index);
|
||||
|
||||
self.WL.extend(&constraint.WL);
|
||||
self.WR.extend(&constraint.WR);
|
||||
self.WO.extend(&constraint.WO);
|
||||
while self.WCG.len() < constraint.WCG.len() {
|
||||
self.WCG.push(vec![]);
|
||||
}
|
||||
while self.WCH.len() < constraint.WCH.len() {
|
||||
self.WCH.push(vec![]);
|
||||
}
|
||||
for (sWC, cWC) in self.WCG.iter_mut().zip(&constraint.WCG) {
|
||||
sWC.extend(cWC);
|
||||
}
|
||||
for (sWC, cWC) in self.WCH.iter_mut().zip(&constraint.WCH) {
|
||||
sWC.extend(cWC);
|
||||
}
|
||||
self.WV.extend(&constraint.WV);
|
||||
self.c += constraint.c;
|
||||
self
|
||||
}
|
||||
}
|
||||
|
||||
impl<F: PrimeField> Sub<&LinComb<F>> for LinComb<F> {
|
||||
type Output = Self;
|
||||
|
||||
fn sub(mut self, constraint: &Self) -> Self {
|
||||
self.highest_a_index = self.highest_a_index.max(constraint.highest_a_index);
|
||||
self.highest_c_index = self.highest_c_index.max(constraint.highest_c_index);
|
||||
self.highest_v_index = self.highest_v_index.max(constraint.highest_v_index);
|
||||
|
||||
self.WL.extend(constraint.WL.iter().map(|(i, weight)| (*i, -*weight)));
|
||||
self.WR.extend(constraint.WR.iter().map(|(i, weight)| (*i, -*weight)));
|
||||
self.WO.extend(constraint.WO.iter().map(|(i, weight)| (*i, -*weight)));
|
||||
while self.WCG.len() < constraint.WCG.len() {
|
||||
self.WCG.push(vec![]);
|
||||
}
|
||||
while self.WCH.len() < constraint.WCH.len() {
|
||||
self.WCH.push(vec![]);
|
||||
}
|
||||
for (sWC, cWC) in self.WCG.iter_mut().zip(&constraint.WCG) {
|
||||
sWC.extend(cWC.iter().map(|(i, weight)| (*i, -*weight)));
|
||||
}
|
||||
for (sWC, cWC) in self.WCH.iter_mut().zip(&constraint.WCH) {
|
||||
sWC.extend(cWC.iter().map(|(i, weight)| (*i, -*weight)));
|
||||
}
|
||||
self.WV.extend(constraint.WV.iter().map(|(i, weight)| (*i, -*weight)));
|
||||
self.c -= constraint.c;
|
||||
self
|
||||
}
|
||||
}
|
||||
|
||||
impl<F: PrimeField> Mul<F> for LinComb<F> {
|
||||
type Output = Self;
|
||||
|
||||
fn mul(mut self, scalar: F) -> Self {
|
||||
for (_, weight) in self.WL.iter_mut() {
|
||||
*weight *= scalar;
|
||||
}
|
||||
for (_, weight) in self.WR.iter_mut() {
|
||||
*weight *= scalar;
|
||||
}
|
||||
for (_, weight) in self.WO.iter_mut() {
|
||||
*weight *= scalar;
|
||||
}
|
||||
for WC in self.WCG.iter_mut() {
|
||||
for (_, weight) in WC {
|
||||
*weight *= scalar;
|
||||
}
|
||||
}
|
||||
for WC in self.WCH.iter_mut() {
|
||||
for (_, weight) in WC {
|
||||
*weight *= scalar;
|
||||
}
|
||||
}
|
||||
for (_, weight) in self.WV.iter_mut() {
|
||||
*weight *= scalar;
|
||||
}
|
||||
self.c *= scalar;
|
||||
self
|
||||
}
|
||||
}
|
||||
|
||||
impl<F: PrimeField> LinComb<F> {
|
||||
/// Create an empty linear combination.
|
||||
pub fn empty() -> Self {
|
||||
Self {
|
||||
highest_a_index: None,
|
||||
highest_c_index: None,
|
||||
highest_v_index: None,
|
||||
WL: vec![],
|
||||
WR: vec![],
|
||||
WO: vec![],
|
||||
WCG: vec![],
|
||||
WCH: vec![],
|
||||
WV: vec![],
|
||||
c: F::ZERO,
|
||||
}
|
||||
}
|
||||
|
||||
/// Add a new instance of a term to this linear combination.
|
||||
pub fn term(mut self, scalar: F, constrainable: Variable) -> Self {
|
||||
match constrainable {
|
||||
Variable::aL(i) => {
|
||||
self.highest_a_index = self.highest_a_index.max(Some(i));
|
||||
self.WL.push((i, scalar))
|
||||
}
|
||||
Variable::aR(i) => {
|
||||
self.highest_a_index = self.highest_a_index.max(Some(i));
|
||||
self.WR.push((i, scalar))
|
||||
}
|
||||
Variable::aO(i) => {
|
||||
self.highest_a_index = self.highest_a_index.max(Some(i));
|
||||
self.WO.push((i, scalar))
|
||||
}
|
||||
Variable::CG { commitment: i, index: j } => {
|
||||
self.highest_c_index = self.highest_c_index.max(Some(i));
|
||||
self.highest_a_index = self.highest_a_index.max(Some(j));
|
||||
while self.WCG.len() <= i {
|
||||
self.WCG.push(vec![]);
|
||||
}
|
||||
self.WCG[i].push((j, scalar))
|
||||
}
|
||||
Variable::CH { commitment: i, index: j } => {
|
||||
self.highest_c_index = self.highest_c_index.max(Some(i));
|
||||
self.highest_a_index = self.highest_a_index.max(Some(j));
|
||||
while self.WCH.len() <= i {
|
||||
self.WCH.push(vec![]);
|
||||
}
|
||||
self.WCH[i].push((j, scalar))
|
||||
}
|
||||
Variable::V(i) => {
|
||||
self.highest_v_index = self.highest_v_index.max(Some(i));
|
||||
self.WV.push((i, scalar));
|
||||
}
|
||||
};
|
||||
self
|
||||
}
|
||||
|
||||
/// Add to the constant c.
|
||||
pub fn constant(mut self, scalar: F) -> Self {
|
||||
self.c += scalar;
|
||||
self
|
||||
}
|
||||
|
||||
/// View the current weights for aL.
|
||||
pub fn WL(&self) -> &[(usize, F)] {
|
||||
&self.WL
|
||||
}
|
||||
|
||||
/// View the current weights for aR.
|
||||
pub fn WR(&self) -> &[(usize, F)] {
|
||||
&self.WR
|
||||
}
|
||||
|
||||
/// View the current weights for aO.
|
||||
pub fn WO(&self) -> &[(usize, F)] {
|
||||
&self.WO
|
||||
}
|
||||
|
||||
/// View the current weights for CG.
|
||||
pub fn WCG(&self) -> &[Vec<(usize, F)>] {
|
||||
&self.WCG
|
||||
}
|
||||
|
||||
/// View the current weights for CH.
|
||||
pub fn WCH(&self) -> &[Vec<(usize, F)>] {
|
||||
&self.WCH
|
||||
}
|
||||
|
||||
/// View the current weights for V.
|
||||
pub fn WV(&self) -> &[(usize, F)] {
|
||||
&self.WV
|
||||
}
|
||||
|
||||
/// View the current constant.
|
||||
pub fn c(&self) -> F {
|
||||
self.c
|
||||
}
|
||||
}
|
||||
|
||||
pub(crate) fn accumulate_vector<F: PrimeField>(
|
||||
accumulator: &mut ScalarVector<F>,
|
||||
values: &[(usize, F)],
|
||||
weight: F,
|
||||
) {
|
||||
for (i, coeff) in values {
|
||||
accumulator[*i] += *coeff * weight;
|
||||
}
|
||||
}
|
||||
121
crypto/evrf/generalized-bulletproofs/src/point_vector.rs
Normal file
121
crypto/evrf/generalized-bulletproofs/src/point_vector.rs
Normal file
@@ -0,0 +1,121 @@
|
||||
use core::ops::{Index, IndexMut};
|
||||
|
||||
use zeroize::Zeroize;
|
||||
|
||||
use ciphersuite::Ciphersuite;
|
||||
|
||||
#[cfg(test)]
|
||||
use multiexp::multiexp;
|
||||
|
||||
use crate::ScalarVector;
|
||||
|
||||
/// A point vector struct with the functionality necessary for Bulletproofs.
|
||||
///
|
||||
/// The math operations for this panic upon any invalid operation, such as if vectors of different
|
||||
/// lengths are added. The full extent of invalidity is not fully defined. Only field access is
|
||||
/// guaranteed to have a safe, public API.
|
||||
#[derive(Clone, PartialEq, Eq, Debug, Zeroize)]
|
||||
pub struct PointVector<C: Ciphersuite>(pub(crate) Vec<C::G>);
|
||||
|
||||
impl<C: Ciphersuite> Index<usize> for PointVector<C> {
|
||||
type Output = C::G;
|
||||
fn index(&self, index: usize) -> &C::G {
|
||||
&self.0[index]
|
||||
}
|
||||
}
|
||||
|
||||
impl<C: Ciphersuite> IndexMut<usize> for PointVector<C> {
|
||||
fn index_mut(&mut self, index: usize) -> &mut C::G {
|
||||
&mut self.0[index]
|
||||
}
|
||||
}
|
||||
|
||||
impl<C: Ciphersuite> PointVector<C> {
|
||||
/*
|
||||
pub(crate) fn add(&self, point: impl AsRef<C::G>) -> Self {
|
||||
let mut res = self.clone();
|
||||
for val in res.0.iter_mut() {
|
||||
*val += point.as_ref();
|
||||
}
|
||||
res
|
||||
}
|
||||
pub(crate) fn sub(&self, point: impl AsRef<C::G>) -> Self {
|
||||
let mut res = self.clone();
|
||||
for val in res.0.iter_mut() {
|
||||
*val -= point.as_ref();
|
||||
}
|
||||
res
|
||||
}
|
||||
|
||||
pub(crate) fn mul(&self, scalar: impl core::borrow::Borrow<C::F>) -> Self {
|
||||
let mut res = self.clone();
|
||||
for val in res.0.iter_mut() {
|
||||
*val *= scalar.borrow();
|
||||
}
|
||||
res
|
||||
}
|
||||
|
||||
pub(crate) fn add_vec(&self, vector: &Self) -> Self {
|
||||
debug_assert_eq!(self.len(), vector.len());
|
||||
let mut res = self.clone();
|
||||
for (i, val) in res.0.iter_mut().enumerate() {
|
||||
*val += vector.0[i];
|
||||
}
|
||||
res
|
||||
}
|
||||
|
||||
pub(crate) fn sub_vec(&self, vector: &Self) -> Self {
|
||||
debug_assert_eq!(self.len(), vector.len());
|
||||
let mut res = self.clone();
|
||||
for (i, val) in res.0.iter_mut().enumerate() {
|
||||
*val -= vector.0[i];
|
||||
}
|
||||
res
|
||||
}
|
||||
*/
|
||||
|
||||
pub(crate) fn mul_vec(&self, vector: &ScalarVector<C::F>) -> Self {
|
||||
debug_assert_eq!(self.len(), vector.len());
|
||||
let mut res = self.clone();
|
||||
for (i, val) in res.0.iter_mut().enumerate() {
|
||||
*val *= vector.0[i];
|
||||
}
|
||||
res
|
||||
}
|
||||
|
||||
#[cfg(test)]
|
||||
pub(crate) fn multiexp(&self, vector: &crate::ScalarVector<C::F>) -> C::G {
|
||||
debug_assert_eq!(self.len(), vector.len());
|
||||
let mut res = Vec::with_capacity(self.len());
|
||||
for (point, scalar) in self.0.iter().copied().zip(vector.0.iter().copied()) {
|
||||
res.push((scalar, point));
|
||||
}
|
||||
multiexp(&res)
|
||||
}
|
||||
|
||||
/*
|
||||
pub(crate) fn multiexp_vartime(&self, vector: &ScalarVector<C::F>) -> C::G {
|
||||
debug_assert_eq!(self.len(), vector.len());
|
||||
let mut res = Vec::with_capacity(self.len());
|
||||
for (point, scalar) in self.0.iter().copied().zip(vector.0.iter().copied()) {
|
||||
res.push((scalar, point));
|
||||
}
|
||||
multiexp_vartime(&res)
|
||||
}
|
||||
|
||||
pub(crate) fn sum(&self) -> C::G {
|
||||
self.0.iter().sum()
|
||||
}
|
||||
*/
|
||||
|
||||
pub(crate) fn len(&self) -> usize {
|
||||
self.0.len()
|
||||
}
|
||||
|
||||
pub(crate) fn split(mut self) -> (Self, Self) {
|
||||
assert!(self.len() > 1);
|
||||
let r = self.0.split_off(self.0.len() / 2);
|
||||
debug_assert_eq!(self.len(), r.len());
|
||||
(self, PointVector(r))
|
||||
}
|
||||
}
|
||||
146
crypto/evrf/generalized-bulletproofs/src/scalar_vector.rs
Normal file
146
crypto/evrf/generalized-bulletproofs/src/scalar_vector.rs
Normal file
@@ -0,0 +1,146 @@
|
||||
use core::ops::{Index, IndexMut, Add, Sub, Mul};
|
||||
|
||||
use zeroize::Zeroize;
|
||||
|
||||
use ciphersuite::group::ff::PrimeField;
|
||||
|
||||
/// A scalar vector struct with the functionality necessary for Bulletproofs.
|
||||
///
|
||||
/// The math operations for this panic upon any invalid operation, such as if vectors of different
|
||||
/// lengths are added. The full extent of invalidity is not fully defined. Only `new`, `len`,
|
||||
/// and field access is guaranteed to have a safe, public API.
|
||||
#[derive(Clone, PartialEq, Eq, Debug)]
|
||||
pub struct ScalarVector<F: PrimeField>(pub(crate) Vec<F>);
|
||||
|
||||
impl<F: PrimeField + Zeroize> Zeroize for ScalarVector<F> {
|
||||
fn zeroize(&mut self) {
|
||||
self.0.zeroize()
|
||||
}
|
||||
}
|
||||
|
||||
impl<F: PrimeField> Index<usize> for ScalarVector<F> {
|
||||
type Output = F;
|
||||
fn index(&self, index: usize) -> &F {
|
||||
&self.0[index]
|
||||
}
|
||||
}
|
||||
impl<F: PrimeField> IndexMut<usize> for ScalarVector<F> {
|
||||
fn index_mut(&mut self, index: usize) -> &mut F {
|
||||
&mut self.0[index]
|
||||
}
|
||||
}
|
||||
|
||||
impl<F: PrimeField> Add<F> for ScalarVector<F> {
|
||||
type Output = ScalarVector<F>;
|
||||
fn add(mut self, scalar: F) -> Self {
|
||||
for s in &mut self.0 {
|
||||
*s += scalar;
|
||||
}
|
||||
self
|
||||
}
|
||||
}
|
||||
impl<F: PrimeField> Sub<F> for ScalarVector<F> {
|
||||
type Output = ScalarVector<F>;
|
||||
fn sub(mut self, scalar: F) -> Self {
|
||||
for s in &mut self.0 {
|
||||
*s -= scalar;
|
||||
}
|
||||
self
|
||||
}
|
||||
}
|
||||
impl<F: PrimeField> Mul<F> for ScalarVector<F> {
|
||||
type Output = ScalarVector<F>;
|
||||
fn mul(mut self, scalar: F) -> Self {
|
||||
for s in &mut self.0 {
|
||||
*s *= scalar;
|
||||
}
|
||||
self
|
||||
}
|
||||
}
|
||||
|
||||
impl<F: PrimeField> Add<&ScalarVector<F>> for ScalarVector<F> {
|
||||
type Output = ScalarVector<F>;
|
||||
fn add(mut self, other: &ScalarVector<F>) -> Self {
|
||||
assert_eq!(self.len(), other.len());
|
||||
for (s, o) in self.0.iter_mut().zip(other.0.iter()) {
|
||||
*s += o;
|
||||
}
|
||||
self
|
||||
}
|
||||
}
|
||||
impl<F: PrimeField> Sub<&ScalarVector<F>> for ScalarVector<F> {
|
||||
type Output = ScalarVector<F>;
|
||||
fn sub(mut self, other: &ScalarVector<F>) -> Self {
|
||||
assert_eq!(self.len(), other.len());
|
||||
for (s, o) in self.0.iter_mut().zip(other.0.iter()) {
|
||||
*s -= o;
|
||||
}
|
||||
self
|
||||
}
|
||||
}
|
||||
impl<F: PrimeField> Mul<&ScalarVector<F>> for ScalarVector<F> {
|
||||
type Output = ScalarVector<F>;
|
||||
fn mul(mut self, other: &ScalarVector<F>) -> Self {
|
||||
assert_eq!(self.len(), other.len());
|
||||
for (s, o) in self.0.iter_mut().zip(other.0.iter()) {
|
||||
*s *= o;
|
||||
}
|
||||
self
|
||||
}
|
||||
}
|
||||
|
||||
impl<F: PrimeField> ScalarVector<F> {
|
||||
/// Create a new scalar vector, initialized with `len` zero scalars.
|
||||
pub fn new(len: usize) -> Self {
|
||||
ScalarVector(vec![F::ZERO; len])
|
||||
}
|
||||
|
||||
pub(crate) fn powers(x: F, len: usize) -> Self {
|
||||
assert!(len != 0);
|
||||
|
||||
let mut res = Vec::with_capacity(len);
|
||||
res.push(F::ONE);
|
||||
res.push(x);
|
||||
for i in 2 .. len {
|
||||
res.push(res[i - 1] * x);
|
||||
}
|
||||
res.truncate(len);
|
||||
ScalarVector(res)
|
||||
}
|
||||
|
||||
/// The length of this scalar vector.
|
||||
#[allow(clippy::len_without_is_empty)]
|
||||
pub fn len(&self) -> usize {
|
||||
self.0.len()
|
||||
}
|
||||
|
||||
/*
|
||||
pub(crate) fn sum(mut self) -> F {
|
||||
self.0.drain(..).sum()
|
||||
}
|
||||
*/
|
||||
|
||||
pub(crate) fn inner_product<'a, V: Iterator<Item = &'a F>>(&self, vector: V) -> F {
|
||||
let mut count = 0;
|
||||
let mut res = F::ZERO;
|
||||
for (a, b) in self.0.iter().zip(vector) {
|
||||
res += *a * b;
|
||||
count += 1;
|
||||
}
|
||||
debug_assert_eq!(self.len(), count);
|
||||
res
|
||||
}
|
||||
|
||||
pub(crate) fn split(mut self) -> (Self, Self) {
|
||||
assert!(self.len() > 1);
|
||||
let r = self.0.split_off(self.0.len() / 2);
|
||||
debug_assert_eq!(self.len(), r.len());
|
||||
(self, ScalarVector(r))
|
||||
}
|
||||
}
|
||||
|
||||
impl<F: PrimeField> From<Vec<F>> for ScalarVector<F> {
|
||||
fn from(vec: Vec<F>) -> Self {
|
||||
Self(vec)
|
||||
}
|
||||
}
|
||||
@@ -0,0 +1,250 @@
|
||||
use rand_core::{RngCore, OsRng};
|
||||
|
||||
use ciphersuite::{group::ff::Field, Ciphersuite, Ristretto};
|
||||
|
||||
use crate::{
|
||||
ScalarVector, PedersenCommitment, PedersenVectorCommitment,
|
||||
transcript::*,
|
||||
arithmetic_circuit_proof::{
|
||||
Variable, LinComb, ArithmeticCircuitStatement, ArithmeticCircuitWitness,
|
||||
},
|
||||
tests::generators,
|
||||
};
|
||||
|
||||
#[test]
|
||||
fn test_zero_arithmetic_circuit() {
|
||||
let generators = generators(1);
|
||||
|
||||
let value = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
let gamma = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
let commitment = (generators.g() * value) + (generators.h() * gamma);
|
||||
let V = vec![commitment];
|
||||
|
||||
let aL = ScalarVector::<<Ristretto as Ciphersuite>::F>(vec![<Ristretto as Ciphersuite>::F::ZERO]);
|
||||
let aR = aL.clone();
|
||||
|
||||
let mut transcript = Transcript::new([0; 32]);
|
||||
let commitments = transcript.write_commitments(vec![], V);
|
||||
let statement = ArithmeticCircuitStatement::<Ristretto>::new(
|
||||
generators.reduce(1).unwrap(),
|
||||
vec![],
|
||||
commitments.clone(),
|
||||
)
|
||||
.unwrap();
|
||||
let witness = ArithmeticCircuitWitness::<Ristretto>::new(
|
||||
aL,
|
||||
aR,
|
||||
vec![],
|
||||
vec![PedersenCommitment { value, mask: gamma }],
|
||||
)
|
||||
.unwrap();
|
||||
|
||||
let proof = {
|
||||
statement.clone().prove(&mut OsRng, &mut transcript, witness).unwrap();
|
||||
transcript.complete()
|
||||
};
|
||||
let mut verifier = generators.batch_verifier();
|
||||
|
||||
let mut transcript = VerifierTranscript::new([0; 32], &proof);
|
||||
let verifier_commmitments = transcript.read_commitments(0, 1);
|
||||
assert_eq!(commitments, verifier_commmitments.unwrap());
|
||||
statement.verify(&mut OsRng, &mut verifier, &mut transcript).unwrap();
|
||||
assert!(generators.verify(verifier));
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_vector_commitment_arithmetic_circuit() {
|
||||
let generators = generators(2);
|
||||
let reduced = generators.reduce(2).unwrap();
|
||||
|
||||
let v1 = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
let v2 = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
let v3 = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
let v4 = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
let gamma = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
let commitment = (reduced.g_bold(0) * v1) +
|
||||
(reduced.g_bold(1) * v2) +
|
||||
(reduced.h_bold(0) * v3) +
|
||||
(reduced.h_bold(1) * v4) +
|
||||
(generators.h() * gamma);
|
||||
let V = vec![];
|
||||
let C = vec![commitment];
|
||||
|
||||
let zero_vec =
|
||||
|| ScalarVector::<<Ristretto as Ciphersuite>::F>(vec![<Ristretto as Ciphersuite>::F::ZERO]);
|
||||
|
||||
let aL = zero_vec();
|
||||
let aR = zero_vec();
|
||||
|
||||
let mut transcript = Transcript::new([0; 32]);
|
||||
let commitments = transcript.write_commitments(C, V);
|
||||
let statement = ArithmeticCircuitStatement::<Ristretto>::new(
|
||||
reduced,
|
||||
vec![LinComb::empty()
|
||||
.term(<Ristretto as Ciphersuite>::F::ONE, Variable::CG { commitment: 0, index: 0 })
|
||||
.term(<Ristretto as Ciphersuite>::F::from(2u64), Variable::CG { commitment: 0, index: 1 })
|
||||
.term(<Ristretto as Ciphersuite>::F::from(3u64), Variable::CH { commitment: 0, index: 0 })
|
||||
.term(<Ristretto as Ciphersuite>::F::from(4u64), Variable::CH { commitment: 0, index: 1 })
|
||||
.constant(-(v1 + (v2 + v2) + (v3 + v3 + v3) + (v4 + v4 + v4 + v4)))],
|
||||
commitments.clone(),
|
||||
)
|
||||
.unwrap();
|
||||
let witness = ArithmeticCircuitWitness::<Ristretto>::new(
|
||||
aL,
|
||||
aR,
|
||||
vec![PedersenVectorCommitment {
|
||||
g_values: ScalarVector(vec![v1, v2]),
|
||||
h_values: ScalarVector(vec![v3, v4]),
|
||||
mask: gamma,
|
||||
}],
|
||||
vec![],
|
||||
)
|
||||
.unwrap();
|
||||
|
||||
let proof = {
|
||||
statement.clone().prove(&mut OsRng, &mut transcript, witness).unwrap();
|
||||
transcript.complete()
|
||||
};
|
||||
let mut verifier = generators.batch_verifier();
|
||||
|
||||
let mut transcript = VerifierTranscript::new([0; 32], &proof);
|
||||
let verifier_commmitments = transcript.read_commitments(1, 0);
|
||||
assert_eq!(commitments, verifier_commmitments.unwrap());
|
||||
statement.verify(&mut OsRng, &mut verifier, &mut transcript).unwrap();
|
||||
assert!(generators.verify(verifier));
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn fuzz_test_arithmetic_circuit() {
|
||||
let generators = generators(32);
|
||||
|
||||
for i in 0 .. 100 {
|
||||
dbg!(i);
|
||||
|
||||
// Create aL, aR, aO
|
||||
let mut aL = ScalarVector(vec![]);
|
||||
let mut aR = ScalarVector(vec![]);
|
||||
while aL.len() < ((OsRng.next_u64() % 8) + 1).try_into().unwrap() {
|
||||
aL.0.push(<Ristretto as Ciphersuite>::F::random(&mut OsRng));
|
||||
}
|
||||
while aR.len() < aL.len() {
|
||||
aR.0.push(<Ristretto as Ciphersuite>::F::random(&mut OsRng));
|
||||
}
|
||||
let aO = aL.clone() * &aR;
|
||||
|
||||
// Create C
|
||||
let mut C = vec![];
|
||||
while C.len() < (OsRng.next_u64() % 16).try_into().unwrap() {
|
||||
let mut g_values = ScalarVector(vec![]);
|
||||
while g_values.0.len() < ((OsRng.next_u64() % 8) + 1).try_into().unwrap() {
|
||||
g_values.0.push(<Ristretto as Ciphersuite>::F::random(&mut OsRng));
|
||||
}
|
||||
let mut h_values = ScalarVector(vec![]);
|
||||
while h_values.0.len() < ((OsRng.next_u64() % 8) + 1).try_into().unwrap() {
|
||||
h_values.0.push(<Ristretto as Ciphersuite>::F::random(&mut OsRng));
|
||||
}
|
||||
C.push(PedersenVectorCommitment {
|
||||
g_values,
|
||||
h_values,
|
||||
mask: <Ristretto as Ciphersuite>::F::random(&mut OsRng),
|
||||
});
|
||||
}
|
||||
|
||||
// Create V
|
||||
let mut V = vec![];
|
||||
while V.len() < (OsRng.next_u64() % 4).try_into().unwrap() {
|
||||
V.push(PedersenCommitment {
|
||||
value: <Ristretto as Ciphersuite>::F::random(&mut OsRng),
|
||||
mask: <Ristretto as Ciphersuite>::F::random(&mut OsRng),
|
||||
});
|
||||
}
|
||||
|
||||
// Generate random constraints
|
||||
let mut constraints = vec![];
|
||||
for _ in 0 .. (OsRng.next_u64() % 8).try_into().unwrap() {
|
||||
let mut eval = <Ristretto as Ciphersuite>::F::ZERO;
|
||||
let mut constraint = LinComb::empty();
|
||||
|
||||
for _ in 0 .. (OsRng.next_u64() % 4) {
|
||||
let index = usize::try_from(OsRng.next_u64()).unwrap() % aL.len();
|
||||
let weight = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
constraint = constraint.term(weight, Variable::aL(index));
|
||||
eval += weight * aL[index];
|
||||
}
|
||||
|
||||
for _ in 0 .. (OsRng.next_u64() % 4) {
|
||||
let index = usize::try_from(OsRng.next_u64()).unwrap() % aR.len();
|
||||
let weight = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
constraint = constraint.term(weight, Variable::aR(index));
|
||||
eval += weight * aR[index];
|
||||
}
|
||||
|
||||
for _ in 0 .. (OsRng.next_u64() % 4) {
|
||||
let index = usize::try_from(OsRng.next_u64()).unwrap() % aO.len();
|
||||
let weight = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
constraint = constraint.term(weight, Variable::aO(index));
|
||||
eval += weight * aO[index];
|
||||
}
|
||||
|
||||
for (commitment, C) in C.iter().enumerate() {
|
||||
for _ in 0 .. (OsRng.next_u64() % 4) {
|
||||
let index = usize::try_from(OsRng.next_u64()).unwrap() % C.g_values.len();
|
||||
let weight = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
constraint = constraint.term(weight, Variable::CG { commitment, index });
|
||||
eval += weight * C.g_values[index];
|
||||
}
|
||||
|
||||
for _ in 0 .. (OsRng.next_u64() % 4) {
|
||||
let index = usize::try_from(OsRng.next_u64()).unwrap() % C.h_values.len();
|
||||
let weight = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
constraint = constraint.term(weight, Variable::CH { commitment, index });
|
||||
eval += weight * C.h_values[index];
|
||||
}
|
||||
}
|
||||
|
||||
if !V.is_empty() {
|
||||
for _ in 0 .. (OsRng.next_u64() % 4) {
|
||||
let index = usize::try_from(OsRng.next_u64()).unwrap() % V.len();
|
||||
let weight = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
constraint = constraint.term(weight, Variable::V(index));
|
||||
eval += weight * V[index].value;
|
||||
}
|
||||
}
|
||||
|
||||
constraint = constraint.constant(-eval);
|
||||
|
||||
constraints.push(constraint);
|
||||
}
|
||||
|
||||
let mut transcript = Transcript::new([0; 32]);
|
||||
let commitments = transcript.write_commitments(
|
||||
C.iter()
|
||||
.map(|C| {
|
||||
C.commit(generators.g_bold_slice(), generators.h_bold_slice(), generators.h()).unwrap()
|
||||
})
|
||||
.collect(),
|
||||
V.iter().map(|V| V.commit(generators.g(), generators.h())).collect(),
|
||||
);
|
||||
|
||||
let statement = ArithmeticCircuitStatement::<Ristretto>::new(
|
||||
generators.reduce(16).unwrap(),
|
||||
constraints,
|
||||
commitments.clone(),
|
||||
)
|
||||
.unwrap();
|
||||
|
||||
let witness = ArithmeticCircuitWitness::<Ristretto>::new(aL, aR, C.clone(), V.clone()).unwrap();
|
||||
|
||||
let proof = {
|
||||
statement.clone().prove(&mut OsRng, &mut transcript, witness).unwrap();
|
||||
transcript.complete()
|
||||
};
|
||||
let mut verifier = generators.batch_verifier();
|
||||
|
||||
let mut transcript = VerifierTranscript::new([0; 32], &proof);
|
||||
let verifier_commmitments = transcript.read_commitments(C.len(), V.len());
|
||||
assert_eq!(commitments, verifier_commmitments.unwrap());
|
||||
statement.verify(&mut OsRng, &mut verifier, &mut transcript).unwrap();
|
||||
assert!(generators.verify(verifier));
|
||||
}
|
||||
}
|
||||
113
crypto/evrf/generalized-bulletproofs/src/tests/inner_product.rs
Normal file
113
crypto/evrf/generalized-bulletproofs/src/tests/inner_product.rs
Normal file
@@ -0,0 +1,113 @@
|
||||
// The inner product relation is P = sum(g_bold * a, h_bold * b, g * (a * b))
|
||||
|
||||
use rand_core::OsRng;
|
||||
|
||||
use ciphersuite::{
|
||||
group::{ff::Field, Group},
|
||||
Ciphersuite, Ristretto,
|
||||
};
|
||||
|
||||
use crate::{
|
||||
ScalarVector, PointVector,
|
||||
transcript::*,
|
||||
inner_product::{P, IpStatement, IpWitness},
|
||||
tests::generators,
|
||||
};
|
||||
|
||||
#[test]
|
||||
fn test_zero_inner_product() {
|
||||
let P = <Ristretto as Ciphersuite>::G::identity();
|
||||
|
||||
let generators = generators::<Ristretto>(1);
|
||||
let reduced = generators.reduce(1).unwrap();
|
||||
let witness = IpWitness::<Ristretto>::new(
|
||||
ScalarVector::<<Ristretto as Ciphersuite>::F>::new(1),
|
||||
ScalarVector::<<Ristretto as Ciphersuite>::F>::new(1),
|
||||
)
|
||||
.unwrap();
|
||||
|
||||
let proof = {
|
||||
let mut transcript = Transcript::new([0; 32]);
|
||||
IpStatement::<Ristretto>::new(
|
||||
reduced,
|
||||
ScalarVector(vec![<Ristretto as Ciphersuite>::F::ONE; 1]),
|
||||
<Ristretto as Ciphersuite>::F::ONE,
|
||||
P::Prover(P),
|
||||
)
|
||||
.unwrap()
|
||||
.clone()
|
||||
.prove(&mut transcript, witness)
|
||||
.unwrap();
|
||||
transcript.complete()
|
||||
};
|
||||
|
||||
let mut verifier = generators.batch_verifier();
|
||||
IpStatement::<Ristretto>::new(
|
||||
reduced,
|
||||
ScalarVector(vec![<Ristretto as Ciphersuite>::F::ONE; 1]),
|
||||
<Ristretto as Ciphersuite>::F::ONE,
|
||||
P::Verifier { verifier_weight: <Ristretto as Ciphersuite>::F::ONE },
|
||||
)
|
||||
.unwrap()
|
||||
.verify(&mut verifier, &mut VerifierTranscript::new([0; 32], &proof))
|
||||
.unwrap();
|
||||
assert!(generators.verify(verifier));
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_inner_product() {
|
||||
// P = sum(g_bold * a, h_bold * b)
|
||||
let generators = generators::<Ristretto>(32);
|
||||
let mut verifier = generators.batch_verifier();
|
||||
for i in [1, 2, 4, 8, 16, 32] {
|
||||
let generators = generators.reduce(i).unwrap();
|
||||
let g = generators.g();
|
||||
assert_eq!(generators.len(), i);
|
||||
let mut g_bold = vec![];
|
||||
let mut h_bold = vec![];
|
||||
for i in 0 .. i {
|
||||
g_bold.push(generators.g_bold(i));
|
||||
h_bold.push(generators.h_bold(i));
|
||||
}
|
||||
let g_bold = PointVector::<Ristretto>(g_bold);
|
||||
let h_bold = PointVector::<Ristretto>(h_bold);
|
||||
|
||||
let mut a = ScalarVector::<<Ristretto as Ciphersuite>::F>::new(i);
|
||||
let mut b = ScalarVector::<<Ristretto as Ciphersuite>::F>::new(i);
|
||||
|
||||
for i in 0 .. i {
|
||||
a[i] = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
b[i] = <Ristretto as Ciphersuite>::F::random(&mut OsRng);
|
||||
}
|
||||
|
||||
let P = g_bold.multiexp(&a) + h_bold.multiexp(&b) + (g * a.inner_product(b.0.iter()));
|
||||
|
||||
let witness = IpWitness::<Ristretto>::new(a, b).unwrap();
|
||||
|
||||
let proof = {
|
||||
let mut transcript = Transcript::new([0; 32]);
|
||||
IpStatement::<Ristretto>::new(
|
||||
generators,
|
||||
ScalarVector(vec![<Ristretto as Ciphersuite>::F::ONE; i]),
|
||||
<Ristretto as Ciphersuite>::F::ONE,
|
||||
P::Prover(P),
|
||||
)
|
||||
.unwrap()
|
||||
.prove(&mut transcript, witness)
|
||||
.unwrap();
|
||||
transcript.complete()
|
||||
};
|
||||
|
||||
verifier.additional.push((<Ristretto as Ciphersuite>::F::ONE, P));
|
||||
IpStatement::<Ristretto>::new(
|
||||
generators,
|
||||
ScalarVector(vec![<Ristretto as Ciphersuite>::F::ONE; i]),
|
||||
<Ristretto as Ciphersuite>::F::ONE,
|
||||
P::Verifier { verifier_weight: <Ristretto as Ciphersuite>::F::ONE },
|
||||
)
|
||||
.unwrap()
|
||||
.verify(&mut verifier, &mut VerifierTranscript::new([0; 32], &proof))
|
||||
.unwrap();
|
||||
}
|
||||
assert!(generators.verify(verifier));
|
||||
}
|
||||
27
crypto/evrf/generalized-bulletproofs/src/tests/mod.rs
Normal file
27
crypto/evrf/generalized-bulletproofs/src/tests/mod.rs
Normal file
@@ -0,0 +1,27 @@
|
||||
use rand_core::OsRng;
|
||||
|
||||
use ciphersuite::{group::Group, Ciphersuite};
|
||||
|
||||
use crate::{Generators, padded_pow_of_2};
|
||||
|
||||
#[cfg(test)]
|
||||
mod inner_product;
|
||||
|
||||
#[cfg(test)]
|
||||
mod arithmetic_circuit_proof;
|
||||
|
||||
/// Generate a set of generators for testing purposes.
|
||||
///
|
||||
/// This should not be considered secure.
|
||||
pub fn generators<C: Ciphersuite>(n: usize) -> Generators<C> {
|
||||
assert_eq!(padded_pow_of_2(n), n, "amount of generators wasn't a power of 2");
|
||||
|
||||
let gens = || {
|
||||
let mut res = Vec::with_capacity(n);
|
||||
for _ in 0 .. n {
|
||||
res.push(C::G::random(&mut OsRng));
|
||||
}
|
||||
res
|
||||
};
|
||||
Generators::new(C::G::random(&mut OsRng), C::G::random(&mut OsRng), gens(), gens()).unwrap()
|
||||
}
|
||||
188
crypto/evrf/generalized-bulletproofs/src/transcript.rs
Normal file
188
crypto/evrf/generalized-bulletproofs/src/transcript.rs
Normal file
@@ -0,0 +1,188 @@
|
||||
use std::io;
|
||||
|
||||
use blake2::{Digest, Blake2b512};
|
||||
|
||||
use ciphersuite::{
|
||||
group::{ff::PrimeField, GroupEncoding},
|
||||
Ciphersuite,
|
||||
};
|
||||
|
||||
use crate::PointVector;
|
||||
|
||||
const SCALAR: u8 = 0;
|
||||
const POINT: u8 = 1;
|
||||
const CHALLENGE: u8 = 2;
|
||||
|
||||
fn challenge<F: PrimeField>(digest: &mut Blake2b512) -> F {
|
||||
// Panic if this is such a wide field, we won't successfully perform a reduction into an unbiased
|
||||
// scalar
|
||||
debug_assert!((F::NUM_BITS + 128) < 512);
|
||||
|
||||
digest.update([CHALLENGE]);
|
||||
let chl = digest.clone().finalize();
|
||||
|
||||
let mut res = F::ZERO;
|
||||
for (i, mut byte) in chl.iter().cloned().enumerate() {
|
||||
for j in 0 .. 8 {
|
||||
let lsb = byte & 1;
|
||||
let mut bit = F::from(u64::from(lsb));
|
||||
for _ in 0 .. ((i * 8) + j) {
|
||||
bit = bit.double();
|
||||
}
|
||||
res += bit;
|
||||
|
||||
byte >>= 1;
|
||||
}
|
||||
}
|
||||
|
||||
// Negligible probability
|
||||
if bool::from(res.is_zero()) {
|
||||
panic!("zero challenge");
|
||||
}
|
||||
|
||||
res
|
||||
}
|
||||
|
||||
/// Commitments written to/read from a transcript.
|
||||
// We use a dedicated type for this to coerce the caller into transcripting the commitments as
|
||||
// expected.
|
||||
#[cfg_attr(test, derive(Clone, PartialEq, Debug))]
|
||||
pub struct Commitments<C: Ciphersuite> {
|
||||
pub(crate) C: PointVector<C>,
|
||||
pub(crate) V: PointVector<C>,
|
||||
}
|
||||
|
||||
impl<C: Ciphersuite> Commitments<C> {
|
||||
/// The vector commitments.
|
||||
pub fn C(&self) -> &[C::G] {
|
||||
&self.C.0
|
||||
}
|
||||
/// The non-vector commitments.
|
||||
pub fn V(&self) -> &[C::G] {
|
||||
&self.V.0
|
||||
}
|
||||
}
|
||||
|
||||
/// A transcript for proving proofs.
|
||||
pub struct Transcript {
|
||||
digest: Blake2b512,
|
||||
transcript: Vec<u8>,
|
||||
}
|
||||
|
||||
/*
|
||||
We define our proofs as Vec<u8> and derive our transcripts from the values we deserialize from
|
||||
them. This format assumes the order of the values read, their size, and their quantity are
|
||||
constant to the context.
|
||||
*/
|
||||
impl Transcript {
|
||||
/// Create a new transcript off some context.
|
||||
pub fn new(context: [u8; 32]) -> Self {
|
||||
let mut digest = Blake2b512::new();
|
||||
digest.update(context);
|
||||
Self { digest, transcript: Vec::with_capacity(1024) }
|
||||
}
|
||||
|
||||
/// Push a scalar onto the transcript.
|
||||
pub fn push_scalar(&mut self, scalar: impl PrimeField) {
|
||||
self.digest.update([SCALAR]);
|
||||
let bytes = scalar.to_repr();
|
||||
self.digest.update(bytes);
|
||||
self.transcript.extend(bytes.as_ref());
|
||||
}
|
||||
|
||||
/// Push a point onto the transcript.
|
||||
pub fn push_point(&mut self, point: impl GroupEncoding) {
|
||||
self.digest.update([POINT]);
|
||||
let bytes = point.to_bytes();
|
||||
self.digest.update(bytes);
|
||||
self.transcript.extend(bytes.as_ref());
|
||||
}
|
||||
|
||||
/// Write the Pedersen (vector) commitments to this transcript.
|
||||
pub fn write_commitments<C: Ciphersuite>(
|
||||
&mut self,
|
||||
C: Vec<C::G>,
|
||||
V: Vec<C::G>,
|
||||
) -> Commitments<C> {
|
||||
for C in &C {
|
||||
self.push_point(*C);
|
||||
}
|
||||
for V in &V {
|
||||
self.push_point(*V);
|
||||
}
|
||||
Commitments { C: PointVector(C), V: PointVector(V) }
|
||||
}
|
||||
|
||||
/// Sample a challenge.
|
||||
pub fn challenge<F: PrimeField>(&mut self) -> F {
|
||||
challenge(&mut self.digest)
|
||||
}
|
||||
|
||||
/// Complete a transcript, yielding the fully serialized proof.
|
||||
pub fn complete(self) -> Vec<u8> {
|
||||
self.transcript
|
||||
}
|
||||
}
|
||||
|
||||
/// A transcript for verifying proofs.
|
||||
pub struct VerifierTranscript<'a> {
|
||||
digest: Blake2b512,
|
||||
transcript: &'a [u8],
|
||||
}
|
||||
|
||||
impl<'a> VerifierTranscript<'a> {
|
||||
/// Create a new transcript to verify a proof with.
|
||||
pub fn new(context: [u8; 32], proof: &'a [u8]) -> Self {
|
||||
let mut digest = Blake2b512::new();
|
||||
digest.update(context);
|
||||
Self { digest, transcript: proof }
|
||||
}
|
||||
|
||||
/// Read a scalar from the transcript.
|
||||
pub fn read_scalar<C: Ciphersuite>(&mut self) -> io::Result<C::F> {
|
||||
let scalar = C::read_F(&mut self.transcript)?;
|
||||
self.digest.update([SCALAR]);
|
||||
let bytes = scalar.to_repr();
|
||||
self.digest.update(bytes);
|
||||
Ok(scalar)
|
||||
}
|
||||
|
||||
/// Read a point from the transcript.
|
||||
pub fn read_point<C: Ciphersuite>(&mut self) -> io::Result<C::G> {
|
||||
let point = C::read_G(&mut self.transcript)?;
|
||||
self.digest.update([POINT]);
|
||||
let bytes = point.to_bytes();
|
||||
self.digest.update(bytes);
|
||||
Ok(point)
|
||||
}
|
||||
|
||||
/// Read the Pedersen (Vector) Commitments from the transcript.
|
||||
///
|
||||
/// The lengths of the vectors are not transcripted.
|
||||
#[allow(clippy::type_complexity)]
|
||||
pub fn read_commitments<C: Ciphersuite>(
|
||||
&mut self,
|
||||
C: usize,
|
||||
V: usize,
|
||||
) -> io::Result<Commitments<C>> {
|
||||
let mut C_vec = Vec::with_capacity(C);
|
||||
for _ in 0 .. C {
|
||||
C_vec.push(self.read_point::<C>()?);
|
||||
}
|
||||
let mut V_vec = Vec::with_capacity(V);
|
||||
for _ in 0 .. V {
|
||||
V_vec.push(self.read_point::<C>()?);
|
||||
}
|
||||
Ok(Commitments { C: PointVector(C_vec), V: PointVector(V_vec) })
|
||||
}
|
||||
|
||||
/// Sample a challenge.
|
||||
pub fn challenge<F: PrimeField>(&mut self) -> F {
|
||||
challenge(&mut self.digest)
|
||||
}
|
||||
|
||||
/// Complete the transcript, returning the advanced slice.
|
||||
pub fn complete(self) -> &'a [u8] {
|
||||
self.transcript
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user