/// <summary>
/// Generates proofs that a token attribute value is not equal to any values in the target array.
/// </summary>
/// <param name="prover">Inequality proof parameters for the token.</param>
/// <param name="target">Target values array.</param>
/// <returns>An inequality proof.</returns>
public static InequalityProof[] GenerateUProveInequalityProofs(EQProofUProveProverData prover, byte[][] target)
{
// Create PedersenCommitments
int commitmentIndex = ClosedPedersenCommitment.GetCommitmentIndex(prover.PPPP.Committed, prover.index);
PedersenCommitment ped = new PedersenCommitment(prover.PPPP, prover.PP, prover.CPV, commitmentIndex);
// Create EqualityProof
CryptoParameters crypto = new CryptoParameters(prover.PPPP.IP);
InequalityProof[] proofs = new InequalityProof[target.Length];
for (int i = 0; i < target.Length; i++)
{
FieldZqElement targetValue = ProtocolHelper.ComputeXi(prover.PPPP.IP, prover.index - 1, target[i]);
proofs[i] = new InequalityProof(new ProverInequalityProofParameters(ped, targetValue, crypto));
}
return(proofs);
}
/// <summary>
/// Verifies a proof that a token attribute value is not equal to a target value.
/// </summary>
/// <param name="verifier">Equality proof parameters for the token.</param>
/// <param name="target">Target value.</param>
/// <param name="eQProof">The inequality proof to verify.</param>
/// <exception cref="InvalidUProveArtifactException">Thrown if the proof is invalid.</exception>
public static void VerifyUProveEqualityProof(EQProofUProveVerifierData verifier, byte[] target, InequalityProof iNeqProof)
{
VerifyUProveEqualityProofs(verifier, new byte[][] { target }, new InequalityProof[] { iNeqProof });
}
/// <summary>
/// Verifies a proof that two tokens share an attribute value, without revealing it.
/// </summary>
/// <param name="verifier1">Equality proof parameters for the first token.</param>
/// <param name="verifier2">Equality proof parameters for the second token.</param>
/// <param name="eQProof">The equality proof to verify.</param>
/// <exception cref="InvalidUProveArtifactException">Thrown if the proof is invalid.</exception>
public static void VerifyUProveEqualityProof(EQProofUProveVerifierData verifier1, EQProofUProveVerifierData verifier2, InequalityProof iNeqProof)
{
int commitmentIndex1 = ClosedPedersenCommitment.GetCommitmentIndex(verifier1.VPPP.Committed, verifier1.index);
int commitmentIndex2 = ClosedPedersenCommitment.GetCommitmentIndex(verifier2.VPPP.Committed, verifier2.index);
ClosedPedersenCommitment closedPed1 = new ClosedPedersenCommitment(verifier1.VPPP.IP, verifier1.PP, commitmentIndex1);
ClosedPedersenCommitment closedPed2 = new ClosedPedersenCommitment(verifier2.VPPP.IP, verifier2.PP, commitmentIndex2);
CryptoParameters crypto = new CryptoParameters(verifier1.VPPP.IP); // Can use prover2.IP
VerifierInequalityProofParameters inequalityVerifier = new VerifierInequalityProofParameters(closedPed1.Value, closedPed2.Value, crypto);
if (!iNeqProof.Verify(inequalityVerifier))
{
throw new InvalidUProveArtifactException("invalid equality proof");
}
}