org.cryptimeleon.math.structures.groups.debug

Class DebugBilinearGroup

java.lang.Object

org.cryptimeleon.math.structures.groups.debug.DebugBilinearGroup

All Implemented Interfaces:

Representable, StandaloneRepresentable, BilinearGroup

public class DebugBilinearGroup
extends java.lang.Object
implements BilinearGroup

A BilinearGroup implementing a fast, but insecure pairing over Zn. Allows for counting group operations and (multi-)exponentiations as well as pairings on the bilinear group level.

The counting capability is implemented by wrapping two LazyBilinearGroups which contain DebugBilinearGroupImpls themselves. All operations are executed in both groups, one counts total group operations and one counts each (multi-)exponentiation as one unit. This allows for tracking both kinds of data.

Nested Class Summary

Nested classes/interfaces inherited from interface org.cryptimeleon.math.structures.groups.elliptic.BilinearGroup

BilinearGroup.Type

Field Summary

Fields

Modifier and Type	Field and Description
protected DebugBilinearMap	bilMap The underlying bilinear map used for applying the pairing function and counting it.
protected LazyBilinearGroup	expMultiExpBilGroup The bilinear group responsible for counting (multi-)exponentiations and group operations outside of those.
protected DebugGroup	g1 The debug group for G1.
protected DebugGroup	g2 The debug group for G2.
protected DebugGroup	gT The debug group for GT.
protected BilinearGroup.Type	pairingType The type of pairing this bilinear group should offer.
protected java.lang.Integer	securityParameter The security level offered by this bilinear group in number of bits.
protected LazyBilinearGroup	totalBilGroup The bilinear group responsible for counting total group operations.

Constructor Summary

Constructors

Constructor and Description
DebugBilinearGroup(BilinearGroup.Type pairingType) Initializes this prime order bilinear group of 128 bit size
DebugBilinearGroup(int securityParameter, BilinearGroup.Type pairingType) Initializes this bilinear group with the given security level, pairing type and prime group order.
DebugBilinearGroup(int securityParameter, BilinearGroup.Type pairingType, int numPrimeFactors) Initializes this bilinear group with the given security level, pairing type, and group order factoring into the given number of prime factors.
DebugBilinearGroup(Representation repr)

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object other)
java.lang.String	formatCounterData() Returns a string with all count data formatted for printing.
BilinearMap	getBilinearMap() Returns the BilinearMap (contains the pairing operation) belonging to this BilinearGroup.
int	getExponentiationWindowSize() Returns the window size used for the non-cached precomputations computed during the exponentiation algorithm if G1, G2, and GT use the same one; otherwise -1.
Group	getG1() Returns the source group G1 associated with this bilinear group.
Group	getG2() Returns the source group G2 associated with this bilinear group.
Group	getGT() Returns the target group GT associated with this bilinear group.
HashIntoGroup	getHashIntoG1() Retrieves a hash function that maps byte arrays to G1.
HashIntoGroup	getHashIntoG2() Retrieves a hash function that maps byte arrays to G2.
HashIntoGroup	getHashIntoGT() Retrieves a hash function that maps byte arrays to GT.
GroupHomomorphism	getHomomorphismG2toG1() Retrieves the homomorphism from G2 to G1 if it exists.
long	getNumPairings() Returns the number of pairings computed in this bilinear group.
BilinearGroup.Type	getPairingType()
int	getPrecomputationWindowSize() Returns the window size used for the precomputations if G1, G2, and GT use the same one; otherwise -1.
Representation	getRepresentation() The representation of this object.
java.lang.Integer	getSecurityLevel()
ExpAlgorithm	getSelectedExpAlgorithm() Returns the selected exponentiation algorithm if G1, G2, and GT use the same one; otherwise null.
MultiExpAlgorithm	getSelectedMultiExpAlgorithm() Returns the selected multi-exponentiation algorithm if G1, G2, and GT use the same one; otherwise null.
int	hashCode()
protected void	init() Initializes the internal debug objects.
void	resetCounters() Resets all counters, including the ones in groups G1, G2, GT.
void	resetNumPairings() Resets pairing counter.
void	setExponentiationWindowSize(int exponentiationWindowSize) Sets the window size used for used for the non-cached precomputations computed during the exponentiation algorithm for G1, G2, and GT at once.
void	setPrecomputationWindowSize(int precomputationWindowSize) Sets the window size used for the cached precomputations for G1, G2, and GT at once.
void	setSelectedExpAlgorithm(ExpAlgorithm selectedExpAlgorithm) Sets the exponentiation algorithm used for G1, G2, and GT at once.
void	setSelectedMultiExpAlgorithm(MultiExpAlgorithm selectedMultiExpAlgorithm) Sets the multi-exponentiation algorithm used for G1, G2, and GT at once.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.cryptimeleon.math.structures.groups.elliptic.BilinearGroup

getHashIntoZGroupExponent, getZn, size

Field Detail

securityParameter

protected java.lang.Integer securityParameter

The security level offered by this bilinear group in number of bits.

pairingType

protected BilinearGroup.Type pairingType

The type of pairing this bilinear group should offer.

totalBilGroup

protected LazyBilinearGroup totalBilGroup

The bilinear group responsible for counting total group operations.

expMultiExpBilGroup

protected LazyBilinearGroup expMultiExpBilGroup

The bilinear group responsible for counting (multi-)exponentiations and group operations outside of those.

bilMap

protected DebugBilinearMap bilMap

The underlying bilinear map used for applying the pairing function and counting it.

g1

protected DebugGroup g1

The debug group for G1.

g2

protected DebugGroup g2

The debug group for G2.

gT

protected DebugGroup gT

The debug group for GT.

Constructor Detail

DebugBilinearGroup

public DebugBilinearGroup(int securityParameter,
                          BilinearGroup.Type pairingType,
                          int numPrimeFactors)

Initializes this bilinear group with the given security level, pairing type, and group order factoring into the given number of prime factors.

Parameters:

securityParameter - the security level in number of bits

pairingType - the type of pairing that should be offered by this bilinear group

numPrimeFactors - the number of prime factors the group order should have

DebugBilinearGroup

public DebugBilinearGroup(int securityParameter,
                          BilinearGroup.Type pairingType)

Initializes this bilinear group with the given security level, pairing type and prime group order.

Parameters:

securityParameter - the security level in number of bits

pairingType - the type of pairing that should be offered by this bilinear group

DebugBilinearGroup

public DebugBilinearGroup(BilinearGroup.Type pairingType)

Initializes this prime order bilinear group of 128 bit size

Parameters:

pairingType - the type of pairing that should be offered by this bilinear group

DebugBilinearGroup

public DebugBilinearGroup(Representation repr)

Method Detail

init

protected void init()

Initializes the internal debug objects.

getG1

public Group getG1()

Description copied from interface: BilinearGroup

Returns the source group G1 associated with this bilinear group.

Specified by:

getG1 in interface BilinearGroup

getG2

public Group getG2()

Description copied from interface: BilinearGroup

Returns the source group G2 associated with this bilinear group.

Specified by:

getG2 in interface BilinearGroup

getGT

public Group getGT()

Description copied from interface: BilinearGroup

Returns the target group GT associated with this bilinear group.

Specified by:

getGT in interface BilinearGroup

getBilinearMap

public BilinearMap getBilinearMap()

Description copied from interface: BilinearGroup

Returns the BilinearMap (contains the pairing operation) belonging to this BilinearGroup.

Specified by:

getBilinearMap in interface BilinearGroup

getHomomorphismG2toG1

public GroupHomomorphism getHomomorphismG2toG1()
                                        throws java.lang.UnsupportedOperationException

Description copied from interface: BilinearGroup

Retrieves the homomorphism from G2 to G1 if it exists.

Specified by:

getHomomorphismG2toG1 in interface BilinearGroup

Throws:

java.lang.UnsupportedOperationException - if no such homomorphism exists or the bilinear group is not configured to support such functionality

getHashIntoG1

public HashIntoGroup getHashIntoG1()
                            throws java.lang.UnsupportedOperationException

Description copied from interface: BilinearGroup

Retrieves a hash function that maps byte arrays to G1.

Specified by:

getHashIntoG1 in interface BilinearGroup

Throws:

java.lang.UnsupportedOperationException - if no such hash function exists or the bilinear group is not configured to support such functionality

getHashIntoG2

public HashIntoGroup getHashIntoG2()
                            throws java.lang.UnsupportedOperationException

Description copied from interface: BilinearGroup

Retrieves a hash function that maps byte arrays to G2.

Specified by:

getHashIntoG2 in interface BilinearGroup

Throws:

java.lang.UnsupportedOperationException - if no such hash function exists or the bilinear group is not configured to support such functionality

getHashIntoGT

public HashIntoGroup getHashIntoGT()
                            throws java.lang.UnsupportedOperationException

Description copied from interface: BilinearGroup

Retrieves a hash function that maps byte arrays to GT.

Specified by:

getHashIntoGT in interface BilinearGroup

Throws:

java.lang.UnsupportedOperationException - if no such hash function exists or the bilinear group is not configured to support such functionality

getSecurityLevel

public java.lang.Integer getSecurityLevel()

Specified by:

getSecurityLevel in interface BilinearGroup

getPairingType

public BilinearGroup.Type getPairingType()

Specified by:

getPairingType in interface BilinearGroup

getRepresentation

public Representation getRepresentation()

Description copied from interface: Representable

The representation of this object. Used for serialization. A convenient way to implement this is using @link ReprUtil

Specified by:

getRepresentation in interface Representable

Returns:

a Representation or null if an equal object can be recreated without any information.

See Also:

Representation

equals

public boolean equals(java.lang.Object other)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

getNumPairings

public long getNumPairings()

Returns the number of pairings computed in this bilinear group.

resetNumPairings

public void resetNumPairings()

Resets pairing counter.

resetCounters

public void resetCounters()

Resets all counters, including the ones in groups G1, G2, GT.

formatCounterData

public java.lang.String formatCounterData()

Returns a string with all count data formatted for printing.

getExponentiationWindowSize

public int getExponentiationWindowSize()

Returns the window size used for the non-cached precomputations computed during the exponentiation algorithm if G1, G2, and GT use the same one; otherwise -1.

setExponentiationWindowSize

public void setExponentiationWindowSize(int exponentiationWindowSize)

Sets the window size used for used for the non-cached precomputations computed during the exponentiation algorithm for G1, G2, and GT at once.

A larger window size leads to an exponential increase in the number of precomputations done during exponentiation. As the precomputations affected by this variable are only temporarily stored during execution of the exponentiation algorithm, we do not recommend setting this too high as the cost of computing the whole window quickly exceeds its performance benefits during the actual exponentiation.

If you want to change the number of cached precomputations, use this#setPrecomputationWindowSize(int).

getPrecomputationWindowSize

public int getPrecomputationWindowSize()

Returns the window size used for the precomputations if G1, G2, and GT use the same one; otherwise -1.

setPrecomputationWindowSize

public void setPrecomputationWindowSize(int precomputationWindowSize)

Sets the window size used for the cached precomputations for G1, G2, and GT at once.

A larger window size leads to an exponential increase in the number of cached precomputations done but can also improve the performance of later exponentiations.

getSelectedMultiExpAlgorithm

public MultiExpAlgorithm getSelectedMultiExpAlgorithm()

Returns the selected multi-exponentiation algorithm if G1, G2, and GT use the same one; otherwise null.

setSelectedMultiExpAlgorithm

public void setSelectedMultiExpAlgorithm(MultiExpAlgorithm selectedMultiExpAlgorithm)

Sets the multi-exponentiation algorithm used for G1, G2, and GT at once.

getSelectedExpAlgorithm

public ExpAlgorithm getSelectedExpAlgorithm()

Returns the selected exponentiation algorithm if G1, G2, and GT use the same one; otherwise null.

setSelectedExpAlgorithm

public void setSelectedExpAlgorithm(ExpAlgorithm selectedExpAlgorithm)

Sets the exponentiation algorithm used for G1, G2, and GT at once.