(feedId, registryVersion, canonicalTimestamp), reconstruct the coalition key as the plain EC sum of the actual signers, and check one Schnorr signature over the canonical message. No chainId is in the message — that is what makes a single signature valid on every chain.
The three implementations
The Starknet contract is a bit-for-bit port of the EVM pipeline, proven by parity tests that verify unmodified EVM-produced signatures on Cairo.
What every verifier enforces
- The
registryVersionexists and has nodes. - Structural guards: non-zero
signaturesRequired,signersBitmap,signature,commitment. popcount(signersBitmap) >= signaturesRequired.- Signers ⊆ the deterministically derived selection set (
groupSize = min(signaturesRequired + redundancyBuffer, nodeCount)). - The aggregate Schnorr signature over the canonical message.