org.cryptimeleon.craco.protocols.arguments.sigma.schnorr.setmembership

Class TwoSidedRangeProof

java.lang.Object

org.cryptimeleon.craco.protocols.arguments.sigma.schnorr.SendThenDelegateFragment

org.cryptimeleon.craco.protocols.arguments.sigma.schnorr.DelegateFragment

org.cryptimeleon.craco.protocols.arguments.sigma.schnorr.setmembership.TwoSidedRangeProof

All Implemented Interfaces:

SchnorrFragment

public class TwoSidedRangeProof
extends DelegateFragment

A fragment for the statement lowerBound <= member <= upperBound.

Nested Class Summary

Nested classes/interfaces inherited from class org.cryptimeleon.craco.protocols.arguments.sigma.schnorr.SendThenDelegateFragment

SendThenDelegateFragment.ProverSpec, SendThenDelegateFragment.ProverSpecBuilder, SendThenDelegateFragment.SendThenDelegateAnnouncement, SendThenDelegateFragment.SubprotocolSpec, SendThenDelegateFragment.SubprotocolSpecBuilder, SendThenDelegateFragment.WitnessValues

Constructor Summary

Constructors

Constructor and Description
TwoSidedRangeProof(org.cryptimeleon.math.expressions.exponent.ExponentExpr member, java.math.BigInteger lowerBound, java.math.BigInteger upperBound, SetMembershipPublicParameters pp) Instantiates the proof for member in [lowerBound, upperBound] (inclusive).
TwoSidedRangeProof(org.cryptimeleon.math.expressions.exponent.ExponentExpr member, int lowerBound, int upperBound, SetMembershipPublicParameters pp) Instantiates the proof for member in [lowerBound, upperBound] (inclusive).
TwoSidedRangeProof(org.cryptimeleon.math.expressions.exponent.ExponentExpr member, org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement lowerBound, org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement upperBound, SetMembershipPublicParameters pp) Instantiates the proof for member in [lowerBound, upperBound] (inclusive).

Method Summary

Modifier and Type	Method and Description
static SetMembershipPublicParameters	generatePublicParameters(org.cryptimeleon.math.structures.groups.elliptic.BilinearGroup group, int base) Generates public parameters to use for this protocol (alternatively, these can be reused from SmallerThanPowerFragment)
protected SendThenDelegateFragment.ProverSpec	provideProverSpecWithNoSendFirst(SchnorrVariableAssignment externalWitnesses, SendThenDelegateFragment.ProverSpecBuilder builder) Run by the prover to set up witness values for variables this fragment proves knowledge of itself (i.e.
protected SendThenDelegateFragment.SubprotocolSpec	provideSubprotocolSpec(SendThenDelegateFragment.SubprotocolSpecBuilder builder)

Methods inherited from class org.cryptimeleon.craco.protocols.arguments.sigma.schnorr.DelegateFragment

provideAdditionalCheck, provideProverSpec, provideSubprotocolSpec, restoreSendFirstValue, simulateSendFirstValue

Methods inherited from class org.cryptimeleon.craco.protocols.arguments.sigma.schnorr.SendThenDelegateFragment

checkTranscript, compressTranscript, debugFragment, decompressTranscript, generateAnnouncement, generateAnnouncementSecret, generateResponse, generateSimulatedTranscript, restoreAnnouncement, restoreResponse

Methods inherited from class java.lang.Object

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

Constructor Detail

TwoSidedRangeProof

public TwoSidedRangeProof(org.cryptimeleon.math.expressions.exponent.ExponentExpr member,
                          org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement lowerBound,
                          org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement upperBound,
                          SetMembershipPublicParameters pp)

Instantiates the proof for member in [lowerBound, upperBound] (inclusive).

Parameters:

member - an expression whose value shall be in the given interval. In the easiest case, this is a SchnorrZnVariable, but it can be any affine linear combination of SchnorrZnVariables

lowerBound - lower bound (inclusive)

upperBound - upper bound (inclusive)

pp - honestly generated public parameters for a set membership proof for {0, ..., base} for an arbitrary integer base (large base means faster protocol). Can be generated by generatePublicParameters(BilinearGroup, int)

TwoSidedRangeProof

public TwoSidedRangeProof(org.cryptimeleon.math.expressions.exponent.ExponentExpr member,
                          int lowerBound,
                          int upperBound,
                          SetMembershipPublicParameters pp)

Instantiates the proof for member in [lowerBound, upperBound] (inclusive).

Parameters:

member - an expression whose value shall be in the given interval. In the easiest case, this is a SchnorrZnVariable, but it can be any affine linear combination of SchnorrZnVariables

lowerBound - lower bound (inclusive)

upperBound - upper bound (inclusive)

pp - honestly generated public parameters for a set membership proof for {0, ..., base} for an arbitrary integer base (large base means faster protocol). Can be generated by generatePublicParameters(BilinearGroup, int)

TwoSidedRangeProof

public TwoSidedRangeProof(org.cryptimeleon.math.expressions.exponent.ExponentExpr member,
                          java.math.BigInteger lowerBound,
                          java.math.BigInteger upperBound,
                          SetMembershipPublicParameters pp)

Instantiates the proof for member in [lowerBound, upperBound] (inclusive).

Parameters:

member - an expression whose value shall be in the given interval. In the easiest case, this is a SchnorrZnVariable, but it can be any affine linear combination of SchnorrZnVariables

lowerBound - lower bound (inclusive)

upperBound - upper bound (inclusive)

pp - honestly generated public parameters for a set membership proof for {0, ..., base} for an arbitrary integer base (large base means faster protocol). Can be generated by generatePublicParameters(BilinearGroup, int)

Method Detail

provideProverSpecWithNoSendFirst

protected SendThenDelegateFragment.ProverSpec provideProverSpecWithNoSendFirst(SchnorrVariableAssignment externalWitnesses,
                                                                               SendThenDelegateFragment.ProverSpecBuilder builder)

Description copied from class: DelegateFragment

Run by the prover to set up witness values for variables this fragment proves knowledge of itself (i.e. those specified in DelegateFragment#provideSubprotocolSpec(SubprotocolSpecBuilder)).

A typical example implementation can be found in SmallerThanPowerFragment.

Specified by:

provideProverSpecWithNoSendFirst in class DelegateFragment

Parameters:

externalWitnesses - the witness values for external variables

builder - helper object to instantiate a ProverSpec

Returns:

the specification of witness values for this fragment's own variables. Returned by ProverSpecBuilder#build().

provideSubprotocolSpec

protected SendThenDelegateFragment.SubprotocolSpec provideSubprotocolSpec(SendThenDelegateFragment.SubprotocolSpecBuilder builder)

Specified by:

provideSubprotocolSpec in class DelegateFragment

generatePublicParameters

public static SetMembershipPublicParameters generatePublicParameters(org.cryptimeleon.math.structures.groups.elliptic.BilinearGroup group,
                                                                     int base)

Generates public parameters to use for this protocol (alternatively, these can be reused from SmallerThanPowerFragment)

Parameters:

group - the group to use for this fragment

base - the desired base (the bigger this is, the larger these parameters become storage-wise, but the faster and shorter the proof becomes)