* 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.
* Have processor report errors during the DKG to the coordinator
* Add RemoveParticipant, InvalidDkgShare to coordinator
* Route DKG blame around coordinator
* Allow public construction of AdditionalBlameMachine
Necessary for upcoming work on handling DKG blame in the processor and
coordinator.
Additionally fixes a publicly reachable panic when commitments parsed with one
ThresholdParams are used in a machine using another set of ThresholdParams.
Renames InvalidProofOfKnowledge to InvalidCommitments.
* Remove unused error from dleq
* Implement support for VerifyBlame in the processor
* Have coordinator send the processor share message relevant to Blame
* Remove desync between processors reporting InvalidShare and ones reporting GeneratedKeyPair
* Route blame on sign between processor and coordinator
Doesn't yet act on it in coordinator.
* Move txn usage as needed for stable Rust to build
* Correct InvalidDkgShare serialization
* Partial move to ff 0.13
It turns out the newly released k256 0.12 isn't on ff 0.13, preventing further
work at this time.
* Update all crates to work on ff 0.13
The provided curves still need to be expanded to fit the new API.
* Finish adding dalek-ff-group ff 0.13 constants
* Correct FieldElement::product definition
Also stops exporting macros.
* Test most new parts of ff 0.13
* Additionally test ff-group-tests with BLS12-381 and the pasta curves
We only tested curves from RustCrypto. Now we test a curve offered by zk-crypto,
the group behind ff/group, and the pasta curves, which is by Zcash (though
Zcash developers are also behind zk-crypto).
* Finish Ed448
Fully specifies all constants, passes all tests in ff-group-tests, and finishes moving to ff-0.13.
* Add RustCrypto/elliptic-curves to allowed git repos
Needed due to k256/p256 incorrectly defining product.
* Finish writing ff 0.13 tests
* Add additional comments to dalek
* Further comments
* Update ethereum-serai to ff 0.13
* Standardize the DLEq serialization function naming
They mismatched from the rest of the project.
This commit is technically incomplete as it doesn't update the dkg crate.
* Rewrite DKG encryption to enable per-message decryption without side effects
This isn't technically true as I already know a break in this which I'll
correct for shortly.
Does update documentation to explain the new scheme. Required for blame.
* Add a verifiable system for blame during the FROST DKG
Previously, if sent an invalid key share, the participant would realize that
and could accuse the sender. Without further evidence, either the accuser
or the accused could be guilty. Now, the accuser has a proof the accused is
in the wrong.
Reworks KeyMachine to return BlameMachine. This explicitly acknowledges how
locally complete keys still need group acknowledgement before the protocol
can be complete and provides a way for others to verify blame, even after a
locally successful run.
If any blame is cast, the protocol is no longer considered complete-able
(instead aborting). Further accusations of blame can still be handled however.
Updates documentation on network behavior.
Also starts to remove "OnDrop". We now use Zeroizing for anything which should
be zeroized on drop. This is a lot more piece-meal and reduces clones.
* Tweak Zeroizing and Debug impls
Expands Zeroizing to be more comprehensive.
Also updates Zeroizing<CachedPreprocess([u8; 32])> to
CachedPreprocess(Zeroizing<[u8; 32]>) so zeroizing is the first thing done
and last step before exposing the copy-able [u8; 32].
Removes private keys from Debug.
* Fix a bug where adversaries could claim to be using another user's encryption keys to learn their messages
Mentioned a few commits ago, now fixed.
This wouldn't have affected Serai, which aborts on failure, nor any DKG
currently supported. It's just about ensuring the DKG encryption is robust and
proper.
* Finish moving dleq from ser/deser to write/read
* Add tests for dkg blame
* Add a FROST test for invalid signature shares
* Batch verify encrypted messages' ephemeral keys' PoP
Encryption used to be inlined into FROST. When writing the documentation, I
realized it was decently hard to review. It also was antagonistic to other
hosted DKG algorithms by not allowing code re-use.
Encryption is now a standalone module, providing clear boundaries and
reusability.
Additionally, the DKG protocol itself used to use the ciphersuite's specified
hash function (with an HKDF to prevent length extension attacks). Now,
RecommendedTranscript is used to achieve much more robust transcripting and
remove the HKDF dependency. This does add Blake2 into all consumers yet is
preferred for its security properties and ease of review.
