Method new_with_given_randomness

delegatable_credentials/src/set_commitment.rs:213–242

Commit to the given set with provided randomness

(
        randomness: E::ScalarField,
        set: BTreeSet<E::ScalarField>,
        srs: &SetCommitmentSRS<E>,
    )

    /// Commit to the given set with provided randomness
    pub fn new_with_given_randomness(
        randomness: E::ScalarField,
        set: BTreeSet<E::ScalarField>,
        srs: &SetCommitmentSRS<E>,
    ) -> Result<(Self, SetCommitmentOpening<E>), DelegationError> {
        let set_size = set.len();

        if set_size > srs.size() {
            return Err(DelegationError::InsufficientSetCommitmentSRSSize(
                set_size,
                srs.size(),
            ));
        }

        let P1_table = WindowTable::new(set_size, srs.get_P1().into_group());
        let s_P1 = srs.get_s_P1().into_group();
        // Check if set contains the trapdoor
        for s in set.iter() {
            if P1_table.multiply(s) == s_P1 {
                return Ok((
                    SetCommitment(P1_table.multiply(&randomness).into_affine()),
                    SetCommitmentOpening::SetWithTrapdoor(randomness, *s),
                ));
            }
        }
        Ok((
            SetCommitment(Self::commit_in_P1(randomness.into_bigint(), set, srs)),
            SetCommitmentOpening::SetWithoutTrapdoor(randomness),
        ))
    }

    /// Commit to the given set when provided with a commitment to the randomness.
    /// It is assumed that `comm_rand` is indeed of the form `r*P1` where `r` is the randomness. A PoK would