org.cryptimeleon.craco.accumulator.nguyen

Class NguyenAccumulatorScheme

java.lang.Object

org.cryptimeleon.craco.accumulator.nguyen.NguyenAccumulatorScheme

All Implemented Interfaces:

AccumulatorScheme<org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement>, org.cryptimeleon.math.hash.UniqueByteRepresentable, org.cryptimeleon.math.serialization.annotations.RepresentationRestorer, org.cryptimeleon.math.serialization.Representable, org.cryptimeleon.math.serialization.StandaloneRepresentable

public class NguyenAccumulatorScheme
extends java.lang.Object
implements AccumulatorScheme<org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement>, org.cryptimeleon.math.hash.UniqueByteRepresentable

An implementation of the Nguyen accumulator.
To instantiate, let a trusted party run setup(BilinearGroup, int), then disseminate the Representation of the resulting NguyenAccumulatorScheme to other parties.

Constructor Summary

Constructors

Constructor and Description
NguyenAccumulatorScheme(org.cryptimeleon.math.structures.groups.elliptic.BilinearGroup bilinearGroup, org.cryptimeleon.math.structures.groups.GroupElement g, org.cryptimeleon.math.structures.groups.GroupElement g_Tilde, org.cryptimeleon.math.structures.groups.GroupElement g_Tilde_Power_S, org.cryptimeleon.math.structures.groups.cartesian.GroupElementVector t)
NguyenAccumulatorScheme(org.cryptimeleon.math.serialization.Representation repr)

Method Summary

Modifier and Type	Method and Description
NguyenDigest	createDigest(java.util.Collection<? extends org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement> setOfValues) Creates the accumulator for the given set of values (essentially a collision-resistant hash of setOfValues).
NguyenWitness	createWitness(AccumulatorDigest digest, java.util.Collection<? extends org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement> setOfAccumulatedValues, org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement valueToComputeWitnessFor) Creates a short witness that can be used to verify set membership in an accumulator.
NguyenWitness	createWitness(java.util.Collection<? extends org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement> setOfAccumulatedValues, org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement valueToComputeWitnessFor)
boolean	equals(java.lang.Object o)
java.lang.Integer	getMaxNumAccumulatedValues() Returns maximum number of AccumulatedTypes that can be simultaneously accumulated in the Accumulator or null if unbounded.
org.cryptimeleon.math.serialization.Representation	getRepresentation()
int	hashCode()
org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement	restoreAccumulatedValue(org.cryptimeleon.math.serialization.Representation repr) Restores an accumulated value of type AccumulatorType from its representation.
AccumulatorDigest	restoreDigest(org.cryptimeleon.math.serialization.Representation repr) Restores an AccumulatorDigest from its representation.
NguyenWitness	restoreWitness(org.cryptimeleon.math.serialization.Representation repr) Restores an AccumulatorWitness from its representation.
static NguyenAccumulatorScheme	setup(org.cryptimeleon.math.structures.groups.elliptic.BilinearGroup bilinearGroup, int size)
static NguyenAccumulatorScheme	setup(int securityParameter, int size)
org.cryptimeleon.math.hash.ByteAccumulator	updateAccumulator(org.cryptimeleon.math.hash.ByteAccumulator accumulator)
NguyenWitness	updateWitness(AccumulatorDigest oldDigest, AccumulatorDigest newDigest, java.util.Collection<? extends org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement> oldAccumulatedSet, java.util.Collection<? extends org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement> newAccumulatedSet, org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement valueToComputeWitnessFor, AccumulatorWitness oldWitnessToBeUpdated) Updates a set membership witness with regard to accumulator changes.
boolean	verify(AccumulatorDigest accumulatorDigest, org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement singleValue, AccumulatorWitness witnessForSingleValue) Verifies that the given singleValue is indeed part of the accumulated set.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.cryptimeleon.craco.accumulator.AccumulatorScheme

delete, insert, restoreFromRepresentation

Methods inherited from interface org.cryptimeleon.math.hash.UniqueByteRepresentable

getUniqueByteRepresentation

Constructor Detail

NguyenAccumulatorScheme

public NguyenAccumulatorScheme(org.cryptimeleon.math.structures.groups.elliptic.BilinearGroup bilinearGroup,
                               org.cryptimeleon.math.structures.groups.GroupElement g,
                               org.cryptimeleon.math.structures.groups.GroupElement g_Tilde,
                               org.cryptimeleon.math.structures.groups.GroupElement g_Tilde_Power_S,
                               org.cryptimeleon.math.structures.groups.cartesian.GroupElementVector t)

NguyenAccumulatorScheme

public NguyenAccumulatorScheme(org.cryptimeleon.math.serialization.Representation repr)

Method Detail

setup

public static NguyenAccumulatorScheme setup(org.cryptimeleon.math.structures.groups.elliptic.BilinearGroup bilinearGroup,
                                            int size)

setup

public static NguyenAccumulatorScheme setup(int securityParameter,
                                            int size)

createDigest

public NguyenDigest createDigest(java.util.Collection<? extends org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement> setOfValues)

Description copied from interface: AccumulatorScheme

Creates the accumulator for the given set of values (essentially a collision-resistant hash of setOfValues).

Specified by:

createDigest in interface AccumulatorScheme<org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement>

createWitness

public NguyenWitness createWitness(AccumulatorDigest digest,
                                   java.util.Collection<? extends org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement> setOfAccumulatedValues,
                                   org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement valueToComputeWitnessFor)

Description copied from interface: AccumulatorScheme

Creates a short witness that can be used to verify set membership in an accumulator.

Specified by:

createWitness in interface AccumulatorScheme<org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement>

setOfAccumulatedValues - the set of values accumulated (including valueToComputeWitnessFor)

valueToComputeWitnessFor - the one value you want to prove is in there

Returns:

a short witness to be used in AccumulatorScheme.verify(AccumulatorDigest, Representable, AccumulatorWitness)

createWitness

public NguyenWitness createWitness(java.util.Collection<? extends org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement> setOfAccumulatedValues,
                                   org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement valueToComputeWitnessFor)

verify

public boolean verify(AccumulatorDigest accumulatorDigest,
                      org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement singleValue,
                      AccumulatorWitness witnessForSingleValue)

Description copied from interface: AccumulatorScheme

Verifies that the given singleValue is indeed part of the accumulated set.

Specified by:

verify in interface AccumulatorScheme<org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement>

updateWitness

public NguyenWitness updateWitness(AccumulatorDigest oldDigest,
                                   AccumulatorDigest newDigest,
                                   java.util.Collection<? extends org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement> oldAccumulatedSet,
                                   java.util.Collection<? extends org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement> newAccumulatedSet,
                                   org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement valueToComputeWitnessFor,
                                   AccumulatorWitness oldWitnessToBeUpdated)

Description copied from interface: AccumulatorScheme

Updates a set membership witness with regard to accumulator changes. Equivalent to recomputing a witness using AccumulatorScheme.createWitness(AccumulatorDigest, Collection, Representable), but this method may be more efficient.

Specified by:

updateWitness in interface AccumulatorScheme<org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement>

Parameters:

oldDigest - the "old" digest

newDigest - the "new" digest

oldAccumulatedSet - the set accumulated in oldDigest

newAccumulatedSet - the set accumulated in newDigest

valueToComputeWitnessFor - the value (present in oldDigest and in newDigest) for which a witness shall be computed

oldWitnessToBeUpdated - a witness for valueToComputeWitnessFor being part of oldDigest

Returns:

a witness for valueToComputeWitnessFor being part of newDigest (same as createWitness(newAccumulatedSet, valueToComputeWitnessFor))

getMaxNumAccumulatedValues

public java.lang.Integer getMaxNumAccumulatedValues()

Description copied from interface: AccumulatorScheme

Returns maximum number of AccumulatedTypes that can be simultaneously accumulated in the Accumulator or null if unbounded.

Specified by:

getMaxNumAccumulatedValues in interface AccumulatorScheme<org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement>

restoreWitness

public NguyenWitness restoreWitness(org.cryptimeleon.math.serialization.Representation repr)

Description copied from interface: AccumulatorScheme

Restores an AccumulatorWitness from its representation.

Specified by:

restoreWitness in interface AccumulatorScheme<org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement>

restoreDigest

public AccumulatorDigest restoreDigest(org.cryptimeleon.math.serialization.Representation repr)

Description copied from interface: AccumulatorScheme

Restores an AccumulatorDigest from its representation.

Specified by:

restoreDigest in interface AccumulatorScheme<org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement>

restoreAccumulatedValue

public org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement restoreAccumulatedValue(org.cryptimeleon.math.serialization.Representation repr)

Description copied from interface: AccumulatorScheme

Restores an accumulated value of type AccumulatorType from its representation.

Specified by:

restoreAccumulatedValue in interface AccumulatorScheme<org.cryptimeleon.math.structures.rings.zn.Zn.ZnElement>

getRepresentation

public org.cryptimeleon.math.serialization.Representation getRepresentation()

Specified by:

getRepresentation in interface org.cryptimeleon.math.serialization.Representable

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

updateAccumulator

public org.cryptimeleon.math.hash.ByteAccumulator updateAccumulator(org.cryptimeleon.math.hash.ByteAccumulator accumulator)

Specified by:

updateAccumulator in interface org.cryptimeleon.math.hash.UniqueByteRepresentable