/GNARK-Circuits

Primary LanguageGo

GNARK Circuits

some zero knowledge circuit implementations using Gnark framework

Circuits

Secp256k1 Ecdsa Signature

  • cosmos-sdk supports secp256k1 curve ecdsa signature scheme
  • gnark also has an implementation of the same but there is no way to generate gnark PrivateKey from sdk private key so use this fork instead, https://github.com/Teja2045/gnark-crypto

Merkle Inclusion proof

  • An inclusion proof verification circuit

  • Data (index of data segment to be proven, IS THERE A WAY TO VERIFY IF THE LEAF DATA MATCHES DATA SEGMENT AT INDEX??), merkleProof as inputs

    merkle.verify(data, merkleproof)

Mimc Hash Function

  • A simple Mimc Hash function verifier with BN254 curve

    Hash(data) == Expected Hash

Signature Verification

  • An eddsa signature verfication that checks if a digital signature is valid or not pubkey.verify(data, signature)

  • data is private input and pubkey, signature are public inputs

    Note: Signature circuit is refactored to have separate prover and verifier. It could be used as a complete example flow.

HTTP Circuit

  • A circuit which requests an endpoint for some data and uses that data for some operations
  • For this to work as expected, the api needs to DETERMINISTIC (an endpoint should return same reponse no matter how many times it's called) !
  • It's like a pure function
  • If the endpoint returns different response, it will lead inconsistency error when compiling the circuit

Sha2 vs crypto/sha256

  • Tried to check hashing compatibility of gnark sha2 implementation with crypto/256. Failed!

Comarisions

  • To check if we can directly compare circuit variables without using assert. Failed!

Conditional Circuit

  • A Zk circuit doesn't support if statement, but we can use api.Select{} for somewhat similar effect
// this is equivalent to toAdd1 := circuit.A_Support == 1 ? circuit.A : 0
toAdd1 := api.Select(circuit.A_Support, circuit.A, 0)

Cube checker

  • A simple circuit that check cube of a number

    x^3 == y

  • X is the private input and y is the public input

Recursive proof (Not completed)

recursive proof design