Method verify

delegatable_credentials/src/set_commitment.rs:393–429

(
        &self,
        subset: BTreeSet<E::ScalarField>,
        set_commitment: &SetCommitment<E>,
        srs: impl Into<&'a PreparedSetCommitmentSRS<E>>,
    )

impl<E: Pairing> SubsetWitness<E> {
    pub fn verify<'a>(
        &self,
        subset: BTreeSet<E::ScalarField>,
        set_commitment: &SetCommitment<E>,
        srs: impl Into<&'a PreparedSetCommitmentSRS<E>>,
    ) -> Result<(), DelegationError> {
        if subset.is_empty() {
            return if self.0 == set_commitment.0 {
                Ok(())
            } else {
                Err(DelegationError::InvalidWitness)
            };
        }
        let srs = srs.into();
        let P1_table = WindowTable::new(subset.len(), srs.get_P1().into_group());
        let s_P1 = srs.get_s_P1().into_group();
        // Check if subset contains the trapdoor
        for s in subset.iter() {
            if P1_table.multiply(s) == s_P1 {
                return Err(DelegationError::ShouldNotContainTrapdoor);
            }
        }
        // Check if e(witness, Ch(subset)) == e(set_commitment, P2) => e(witness, Ch(subset))*e(-set_commitment, P2) == 1
        if E::multi_pairing(
            [self.0, (-set_commitment.0.into_group()).into_affine()],
            [
                E::G2Prepared::from(srs.eval_P2(subset)),
                srs.prepared_P2.clone(),
            ],
        )
        .is_zero()
        {
            Ok(())
        } else {
            Err(DelegationError::InvalidWitness)
        }
    }
}

impl<E: Pairing> AggregateSubsetWitness<E> {