An archive of all GlobalSessions is necessary to check for faults. The storage
cost is also minimal. While it should be avoided if it can be, it can't be
here.
Cosigns was an archive of every single cosign ever received. By scoping
NetworksLatestCosignedBlock to be by the global session, we have the latest
cosign for each network in a session (valid to replace all prior cosigns by
that network within that session, even for the purposes of fault) and
automatically have the notable cosigns indexed (as they are the latest ones
within their session). This not only saves space yet also allows optimizing
evaluation a bit.
Not only cleans the existing cosign code but enables non-Serai-coordinators to
evaluate cosigns if they gain access to a feed of them (such as over an RPC).
This would let centralized services not only track the finalized chain yet the
cosigned chain without directly running a coordinator.
Still being wrapped up.
* 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.
* Clear upons upon round, not block
* Cache the proposal for a round
* Rebase onto develop, which reverted this PR, and re-apply this PR
* Set participation upon participation instead of constantly recalculating
* Cache message instances
* Add missing txn commit
Identified by @akildemir.
* Correct clippy lint identified upon rebase
* Fix tendermint chain sync (#581)
* fix p2p Reqres protocol
* stabilize tributary chain sync
* fix pr comments
---------
Co-authored-by: akildemir <34187742+akildemir@users.noreply.github.com>
We prior required they had the same encoding, yet this ensures they do by
making them one and the same. This does require an large, ugly, From/TryInto
block which is deemed preferable for moving this more and more into syntax
(from semantics).
Further improvements (notably re: Extra) is possible, and this already lets us
strip some members from the Call enum.
* Rewrite tendermint's message handling loop to much more clearly match the paper
No longer checks relevant branches upon messages, yet all branches upon any
state change. This is slower, yet easier to review and likely without one or
two rare edge cases.
When reviewing, please see page 5 of https://arxiv.org/pdf/1807.04938.pdf.
Lines from the specified algorithm can be found in the code by searching for
"// L".
* Sane rebroadcasting of consensus messages
Instead of broadcasting the last n messages on the Tributary side of things, we
now have the machine rebroadcast the message tape for the current block.
* Only rebroadcast messages which didn't error in some way
* Only rebroadcast our own messages for tendermint
Instead of saving, for every sent message, if it was sent or not, we track the
latest block/round participated in. These two keys are comprehensive to all
prior block/rounds. We then use three keys for the latest round's
proposal/prevote/precommit, enabling tracking current state as necessary to
prevent equivocations with just 5 keys.
The storage of the latest three messages also enables proper rebroadcasting of
the current round (not implemented in this commit).
Online validators should inherently have them. Offline validators will receive
from the sync protocol.
This does somewhat eliminate the class of nodes who would follow the blockchain
(without validating it), yet that's fine for the performance benefit.
