# Module binius_core::protocols

source · ## Expand description

Implementations of various virtual polynomial protocols.

A virtual polynomial protocol is subprotocol of a polynomial IOP. See DP23 Definition 4.7 for a formal definition. Each protocol has a prover-side implementation and a verifier-side implementation. These protocols are all public-coin and made non-interactive by the Fiat-Shamir transformation. Thus, the prover-side implementations all simulate a verifier in order to accurately construct the transcript.

The protocol implementations have separate functions for each round. We model the virtual polynomial protocols this way because in many settings we want the ability to batch together multiple protocols at different rounds. For example, if we had one sumcheck claim for an $\nu$-variate polynomial and one sumcheck claim for a $\nu - 1$-variate polynomial, we would want to run one sumcheck round on the first claim, then batch the remaining rounds with the second claim.

Each verifier round proceeds as

- Receive the round message (ie. read it from the non-interactive proof)
- Send the round message to the challenger
- Sample challenge from the challenger
- Verify the round message and reduce old claims, message, and challenge to new claims

Each prover round proceeds as

- (Simulate verifier’s last round) Send last round message to the challenger
- (Simulate verifier’s last round) Sample challenge from the challenger
- (Simulate verifier’s last round) Reduce old claims, message, and challenge to new claims
- Compute the round message

## Modules§

- The multivariate evalcheck polynomial protocol.
- Implementation of the Fast Reed–Solomon IOPP (FRI) over binary fields.
- The grand product argument protocol based on a GKR-instantiation.
- The product check polynomial protocol based on reduction to two grand product instances.
- The multivariate sumcheck polynomial protocol, special cased when the sumcheck is part of the GKR Protocol.
- An interactive protocol for proving/verifying evaluation claims on virtual polynomials.
- Lasso lookup.
- The multiset check polynomial protocol.
- The product check polynomial protocol.
- The multivariate sumcheck polynomial protocol.
- The zerocheck interactive reduction, as defined in DP23, Section 4.