org.cryptimeleon.craco.protocols.arguments.sigma

Interface ChallengeSpace

All Superinterfaces:

org.cryptimeleon.math.serialization.annotations.RepresentationRestorer

All Known Implementing Classes:

ZnChallengeSpace

public interface ChallengeSpace
extends org.cryptimeleon.math.serialization.annotations.RepresentationRestorer

Method Summary

Modifier and Type	Method and Description
Challenge	generateRandomChallenge()
Challenge	hashIntoChallengeSpace(byte[] bytes) Hashes the given bytes into this challenge space (in a random-oracle-like manner).
Challenge	mapIntoChallengeSpace(byte[] bytes) Creates a challenge from the given byte[].
Challenge	restoreChallenge(org.cryptimeleon.math.serialization.Representation repr) Restores a given challenge from representation.
default java.lang.Object	restoreFromRepresentation(java.lang.reflect.Type type, org.cryptimeleon.math.serialization.Representation repr)
java.math.BigInteger	size() Returns the size of the challenge space.
Challenge	subtract(Challenge challengeToSplit, Challenge share1) Returns the unique challenge share2 such that subtract(challengeToSplit, share2).equals(share1).

Method Detail

generateRandomChallenge

Challenge generateRandomChallenge()

size

java.math.BigInteger size()
                   throws java.lang.UnsupportedOperationException

Returns the size of the challenge space. null for infinite size, throws UnsupportedOperationException if unknown.

Throws:

java.lang.UnsupportedOperationException

restoreChallenge

Challenge restoreChallenge(org.cryptimeleon.math.serialization.Representation repr)

Restores a given challenge from representation.

restoreFromRepresentation

default java.lang.Object restoreFromRepresentation(java.lang.reflect.Type type,
                                                   org.cryptimeleon.math.serialization.Representation repr)

Specified by:

restoreFromRepresentation in interface org.cryptimeleon.math.serialization.annotations.RepresentationRestorer

mapIntoChallengeSpace

Challenge mapIntoChallengeSpace(byte[] bytes)

Creates a challenge from the given byte[].

Given two random byte[] of the same (arbitrary) length, it should be unlikely that their challenge collides.

hashIntoChallengeSpace

Challenge hashIntoChallengeSpace(byte[] bytes)

Hashes the given bytes into this challenge space (in a random-oracle-like manner). If two challenge spaces are equal, then the behavior of this method is consistent.

subtract

Challenge subtract(Challenge challengeToSplit,
                   Challenge share1)
            throws java.lang.UnsupportedOperationException

Returns the unique challenge share2 such that subtract(challengeToSplit, share2).equals(share1). This is akin to secret sharing. For all challengeToSplit, subtract(challengeToSplit, generateRandomChallenge()) shall be distributed like generateRandomChallenge().

Throws:

java.lang.UnsupportedOperationException - if this challenge space does not support splitting challenges.