// Given a witness and secret nonces, respond to a challenge proving the equation holds w.r.t the witness
internal static ScalarVector Respond(ScalarVector witness, ScalarVector secretNonces, Scalar challenge)
{
// blinding terms are required in order to protect the witness (unless the
// challenge is 0), so only respond if that is the case
foreach (var secretNonce in secretNonces)
{
CryptoGuard.NotZero(nameof(secretNonce), secretNonce);
}
// Taking the discrete logarithms of both sides of the verification
// equation with respect to G results in a formula for the response s
// given k, e and x:
// s = k + ex
return(secretNonces + challenge * witness);
}
public Proof(GroupElementVector publicNonces, IEnumerable <ScalarVector> allResponses)
{
CryptoGuard.NotNullOrInfinity(nameof(publicNonces), publicNonces);
Guard.NotNullOrEmpty(nameof(allResponses), allResponses);
// Ensure allResponses isn't jagged
var n = allResponses.First().Count();
Guard.True(nameof(allResponses), allResponses.All(responses => Guard.NotNullOrEmpty(nameof(responses), responses).Count() == n));
// Ensure there is a vector of response scalars for each public nonce
Guard.True(nameof(allResponses), allResponses.Count() == publicNonces.Count());
PublicNonces = publicNonces;
Responses = allResponses;
}
public void CommitPublicNonces(IEnumerable <GroupElement> nonces)
{
CryptoGuard.NotInfinity(nameof(nonces), nonces);
AddMessages(NonceTag, nonces.Select(x => x.ToBytes()));
}
public Statement(GroupElement publicPoint, IEnumerable <GroupElement> generators)
{
PublicPoint = CryptoGuard.NotNullOrInfinity(nameof(publicPoint), publicPoint);
Generators = CryptoGuard.NotNullOrInfinity(nameof(generators), generators);
}
public void CommitStatement(LinearRelation.Statement statement)
{
Guard.NotNull(nameof(statement.Generators), statement.Generators);
CryptoGuard.NotNullOrInfinity(nameof(statement.PublicPoints), statement.PublicPoints);
AddMessages(StatementTag, statement.PublicPoints.Select(x => x.ToBytes()).Concat(statement.Generators.Select(x => x.ToBytes())));
}
