Cryptographic commit–reveal, with zero-knowledge proofs, in pure Python.

§ 1

Where it fits in 2026

Any protocol where one party must bind to a choice without yet announcing it. The two-phase structure removes the timing advantage that would otherwise let later participants peek at earlier ones — the shared root cause behind MEV, copy-trading, and last-look games across the agent economy.

• Anti-MEV & fair ordering

  Order intents are committed during a sealed window, then revealed for matching. Front-runners cannot sandwich or react to orders they have not yet seen — the timing edge that MEV extracts simply is not there.

  — MEV-resistant DEX / intent design

• Verifiable on-chain AI

  When independent agents must answer without copying each other, each commits to its output first and reveals after the window closes. A Schnorr ZKP proves "this reveal matches my commitment" without re-broadcasting the payload.

  — DFPN-style inference networks

• Sealed-bid auctions (RWA, NFTs)

  Bidders publish a commitment to their bid; nobody, including the auctioneer, can read it. After the deadline, they reveal. No late bidder could have peeked at earlier bids.

  — docs/use-cases.md: "Auction Systems"

• RNG & prediction-market resolution

  Parties commit to seeds or outcomes, then reveal; the result is a hash of all reveals — uniform and unmanipulable while one party is honest. Resolvers commit before an outcome is public, removing the last-look edge.

  — commit-reveal RNG / market resolution

§ 3

A worked example

Lifted verbatim from the README. The library refuses to start with an insecure hash — md5 and sha1 raise SecurityError at construction time.

Reveal is timing-safe: comparison goes through hmac.compare_digest, not ==.

§ 4

API at a glance

One class, three pure-function methods for the commit-reveal core, three more for the ZKP path. ZKP methods raise ValueError unless the scheme was constructed with use_zkp=True.

class CommitRevealScheme:
    def __init__(
        self,
        hash_algorithm: str = "sha256",
        use_zkp: bool = False,
        enable_audit: bool = True,
    ): ...

    # commit-reveal core
    def commit(value, salt=None) -> tuple[bytes, bytes]: ...
    def reveal(value, salt, commitment) -> bool: ...
    def verify(value, salt, commitment) -> bool:    # alias of reveal
        ...

    # Schnorr ZKP on secp256k1 (requires use_zkp=True)
    def create_zkp_proof(value, salt, commitment) -> tuple: ...
    def verify_zkp_proof(
        commitment, public_key, R_compressed, challenge, response
    ) -> bool: ...
    def verify_commitment_consistency(
        value, salt, commitment, public_key
    ) -> bool: ...

# raised exceptions:
#   ValidationError  — invalid input
#   SecurityError    — insecure hash (md5, sha1) or unsafe operation