Multi schnorr circuit Implementation gnark

[Architsharma7]

Multi-schnorr circuit implementation using gnark over the babyjubjub curve and using the MiMC hash function.

Motivation:

• Batch-verify schnorr signatures while handling non-participating validators through conditional constraints.
• Prove that each active signer belongs to a committed validator set (Merkle root).

Relevant information:

• Validator set: S of size MaxK = 2^Depth, with depth as the depth of merkle tree of validator pubic key hashes and inactive entries gated by IsIgnore = 1.
• Merkle binding: One-time MiMC tree built from S (leaf = MiMC(Ax, Ay)), less computation complexity than verifying each membership proof if k is large (eg. 2/3).
• Membership: Membership (per candidate): enforce that (Ax,Ay) matches exactly one leaf in S
• Verification: For each active entry, enforce [S]G = R + [e]A, with e = MiMC(Rx, Ry, Ax, Ay, Message).
• Counting: SumValid accumulates all active, valid signatures, that can be compared against threshold in verifying smart contract

Files added:

• circuit.go: Multi-Schnorr circuit definition.

• compile_test.go: ensures compilation and constraint reporting.

• profile_test.go: generates gnark.pprof for constraint profiling.

To run:

# Compile test
go test -run TestCompile -v

# Profile test
go test -run TestProfileCircuit -v 
go tool pprof -http=:8080 gnark.pprof

[socket-security]

Review the following changes in direct dependencies. Learn more about Socket for GitHub.

Diff	Package	Supply Chain Security	Vulnerability	Quality	Maintenance	License
	github.com/​consensys/​gnark@​v0.14.0
	github.com/​consensys/​gnark-crypto@​v0.19.0

View full report

[fleupold]

Why is this needed? The circuit guarantees that the candidate list cannot change between the two for loops. So if in the first for loop we were able to construct the correct merkle root, we know that all candidates are part of the merkle tree. No need to re-check it here.