public static final PolynomialMembershipProofSystem getInstance(
final SigmaChallengeGenerator challengeGenerator,
final Subset members,
final PedersenCommitmentScheme pedersenCS) {
if (challengeGenerator == null || members == null || pedersenCS == null) {
throw new IllegalArgumentException();
}
if (!(members.getSuperset() instanceof ZModPrime)
|| pedersenCS.getCyclicGroup().getOrder() != members.getSuperset().getOrder()) {
throw new IllegalArgumentException();
}
if (!challengeGenerator.getChallengeSpace().isEquivalent(pedersenCS.getMessageSpace())) {
throw new IllegalArgumentException();
}
return new PolynomialMembershipProofSystem(challengeGenerator, members, pedersenCS);
}
private PolynomialMembershipProofSystem(
final SigmaChallengeGenerator challengeGenerator,
final Subset members,
final PedersenCommitmentScheme pedersenCS) {
super(challengeGenerator);
this.members = members;
final Element[] roots = new Element[this.members.getOrder().intValue()];
int i = 0;
for (Element member : this.members.getElements()) {
roots[i++] = member;
}
PolynomialElement polynomial =
PolynomialSemiRing.getInstance((ZModPrime) members.getSuperset())
.getElementByRoots(Tuple.getInstance(roots));
this.pepsi =
PolynomialEvaluationProofSystem.getInstance(challengeGenerator, polynomial, pedersenCS);
}