org.cryptimeleon.craco.protocols.arguments.sigma.partial

Class OrProof

java.lang.Object

org.cryptimeleon.craco.protocols.arguments.sigma.partial.OrProof

All Implemented Interfaces:

InteractiveArgument, SigmaProtocol, TwoPartyProtocol

public class OrProof
extends java.lang.Object
implements SigmaProtocol

The OR composition of two SigmaProtocols. Meaning that in order to run this protocol, the prover must have knowledge of valid secret input for one of the two (sub)protocols.
To use:

1. Instantiate this protocol with the two protocols to compose.
2. The common input for this protocol is a CommonInput.CommonInputVector of the subprotocols' common inputs
3. The secret input for this protocol is a OrProof.OrProofSecretInput (which encapsulates a witness for either the first or the second protocol)

Depending on your use-case, ProofOfPartialKnowledge may be more convenient for you.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	OrProof.OrProofResponse
static class	OrProof.OrProofSecretInput

Field Summary

Fields

Modifier and Type	Field and Description
SigmaProtocol	protocol0
SigmaProtocol	protocol1

Fields inherited from interface org.cryptimeleon.craco.protocols.arguments.InteractiveArgument

PROVER_ROLE, VERIFIER_ROLE

Constructor Summary

Constructors

Constructor and Description
OrProof(SigmaProtocol protocol0, SigmaProtocol protocol1)

Method Summary

Modifier and Type	Method and Description
org.cryptimeleon.math.expressions.bool.BooleanExpression	checkTranscriptAsExpression(CommonInput commonInput, Announcement announcement, Challenge challenge, Response response) Used by the verifier to check whether the given transcript is accepting.
void	debugProof(CommonInput commonInput, SecretInput secretInput) Checks if commonInput and secretInput are valid inputs for this protocol.
Announcement	generateAnnouncement(CommonInput commonInput, SecretInput secretInput, AnnouncementSecret announcementSecret) Used by the prover to generate an announcement (the first message sent in the protocol).
AnnouncementSecret	generateAnnouncementSecret(CommonInput commonInput, SecretInput secretInput) Used by the prover to generate a secret value that will be input for future method calls.
Response	generateResponse(CommonInput commonInput, SecretInput secretInput, Announcement announcement, AnnouncementSecret announcementSecret, Challenge challenge) Used by the prover to generate a response (the third and last message sent in the protocol).
SigmaProtocolTranscript	generateSimulatedTranscript(CommonInput commonInput, Challenge challenge) Generates a random transcript with the same distribution as an honestly generated one that contains the given Challenge.
ChallengeSpace	getChallengeSpace(CommonInput commonInput) Returns the challenge space used by this protocol.
Announcement	restoreAnnouncement(CommonInput commonInput, org.cryptimeleon.math.serialization.Representation repr)
Response	restoreResponse(CommonInput commonInput, Announcement announcement, Challenge challenge, org.cryptimeleon.math.serialization.Representation repr)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.cryptimeleon.craco.protocols.arguments.sigma.SigmaProtocol

checkTranscript, checkTranscript, compressTranscript, decompressTranscript, generateChallenge, getFirstMessageRole, getProverInstance, getVerifierInstance, instantiateProtocol, restoreChallenge, restoreTranscript

Methods inherited from interface org.cryptimeleon.craco.protocols.arguments.InteractiveArgument

getRoleNames, instantiateProver, instantiateVerifier

Methods inherited from interface org.cryptimeleon.craco.protocols.TwoPartyProtocol

runProtocolLocally

Field Detail

protocol0

public final SigmaProtocol protocol0

protocol1

public final SigmaProtocol protocol1

Constructor Detail

OrProof

public OrProof(SigmaProtocol protocol0,
               SigmaProtocol protocol1)

Method Detail

generateAnnouncementSecret

public AnnouncementSecret generateAnnouncementSecret(CommonInput commonInput,
                                                     SecretInput secretInput)

Description copied from interface: SigmaProtocol

Used by the prover to generate a secret value that will be input for future method calls.

For example, for an implementation of the original Schnorr protocol, the announcement secret would be a random exponent r.

Specified by:

generateAnnouncementSecret in interface SigmaProtocol

Parameters:

commonInput - input to the overall protocol that both prover and verifier use

secretInput - input to the overall protocol that only the prover gets

Returns:

a secret (internal) value used for generating announcements and responses

generateAnnouncement

public Announcement generateAnnouncement(CommonInput commonInput,
                                         SecretInput secretInput,
                                         AnnouncementSecret announcementSecret)

Description copied from interface: SigmaProtocol

Used by the prover to generate an announcement (the first message sent in the protocol).

Specified by:

generateAnnouncement in interface SigmaProtocol

getChallengeSpace

public ChallengeSpace getChallengeSpace(CommonInput commonInput)

Description copied from interface: SigmaProtocol

Returns the challenge space used by this protocol.

Specified by:

getChallengeSpace in interface SigmaProtocol

generateResponse

public Response generateResponse(CommonInput commonInput,
                                 SecretInput secretInput,
                                 Announcement announcement,
                                 AnnouncementSecret announcementSecret,
                                 Challenge challenge)

Description copied from interface: SigmaProtocol

Used by the prover to generate a response (the third and last message sent in the protocol).

Specified by:

generateResponse in interface SigmaProtocol

checkTranscriptAsExpression

public org.cryptimeleon.math.expressions.bool.BooleanExpression checkTranscriptAsExpression(CommonInput commonInput,
                                                                                            Announcement announcement,
                                                                                            Challenge challenge,
                                                                                            Response response)

Description copied from interface: SigmaProtocol

Used by the verifier to check whether the given transcript is accepting. The result is a BooleanExpression, which makes it easier to provide optimization for composed protocols.

Specified by:

checkTranscriptAsExpression in interface SigmaProtocol

Returns:

a BooleanExpression without variables that evaluates to true (for accepting transcripts) or false.

generateSimulatedTranscript

public SigmaProtocolTranscript generateSimulatedTranscript(CommonInput commonInput,
                                                           Challenge challenge)

Description copied from interface: SigmaProtocol

Generates a random transcript with the same distribution as an honestly generated one that contains the given Challenge.

Specified by:

generateSimulatedTranscript in interface SigmaProtocol

restoreAnnouncement

public Announcement restoreAnnouncement(CommonInput commonInput,
                                        org.cryptimeleon.math.serialization.Representation repr)

Specified by:

restoreAnnouncement in interface SigmaProtocol

restoreResponse

public Response restoreResponse(CommonInput commonInput,
                                Announcement announcement,
                                Challenge challenge,
                                org.cryptimeleon.math.serialization.Representation repr)

Specified by:

restoreResponse in interface SigmaProtocol

debugProof

public void debugProof(CommonInput commonInput,
                       SecretInput secretInput)

Description copied from interface: InteractiveArgument

Checks if commonInput and secretInput are valid inputs for this protocol. Use for debugging. Throws an exception if something is wrong.

Specified by:

debugProof in interface InteractiveArgument