org.cryptimeleon.math.structures.groups.counting

Class CountingGroupElementImpl

java.lang.Object

org.cryptimeleon.math.structures.groups.counting.CountingGroupElementImpl

All Implemented Interfaces:

UniqueByteRepresentable, Representable, GroupElementImpl

public class CountingGroupElementImpl
extends java.lang.Object
implements GroupElementImpl

An element of CountingGroupImpl able to count group operations, inversions and squarings it is involved with. The actual group operations are realized via a Zn element.

See Also:

CountingGroupElement, CountingGroupImpl

Field Summary

Fields

Modifier and Type	Field and Description
protected Zn.ZnElement	elem The underlying Zn element that realizes the actual group operations.
protected CountingGroupImpl	group The group this element belongs to.

Constructor Summary

Constructors

Constructor and Description
CountingGroupElementImpl(CountingGroupImpl group, Zn.ZnElement elem) Initializes this element as belonging to the given group and using the given Zn element for its group operations.

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object o)
Representation	getRepresentation() The representation of this object.
GroupImpl	getStructure() Retrieves the group this element belongs to.
int	hashCode()
GroupElementImpl	inv() Calculates the inverse of this group element.
boolean	isNeutralElement() Returns true iff this is the neutral element of the group.
GroupElementImpl	op(GroupElementImpl e) Calculates the result of this op e.
protected GroupElementImpl	op(GroupElementImpl e, boolean count) Allows to configure whether to count this operation.
GroupElementImpl	pow(java.math.BigInteger k) Calculates the result of applying the group operation k times.
protected GroupElementImpl	pow(java.math.BigInteger k, boolean count) Allows to configure whether to count this exponentiation.
java.lang.String	toString()
ByteAccumulator	updateAccumulator(ByteAccumulator accumulator) Updates the ByteAccumulator with the unique byte representation of this object.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.cryptimeleon.math.structures.groups.GroupElementImpl

square

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

getUniqueByteRepresentation

Field Detail

elem

protected Zn.ZnElement elem

The underlying Zn element that realizes the actual group operations.

group

protected CountingGroupImpl group

The group this element belongs to.

Constructor Detail

CountingGroupElementImpl

public CountingGroupElementImpl(CountingGroupImpl group,
                                Zn.ZnElement elem)

Initializes this element as belonging to the given group and using the given Zn element for its group operations.

Parameters:

group - The group this element belongs to.

elem - The Zn element through which the group operations are done.

Method Detail

getStructure

public GroupImpl getStructure()

Description copied from interface: GroupElementImpl

Retrieves the group this element belongs to.

Specified by:

getStructure in interface GroupElementImpl

inv

public GroupElementImpl inv()

Description copied from interface: GroupElementImpl

Calculates the inverse of this group element.

Specified by:

inv in interface GroupElementImpl

Returns:

an element x such that x.op(this).equals(getStructure().getNeutralElement())

op

protected GroupElementImpl op(GroupElementImpl e,
                              boolean count)

Allows to configure whether to count this operation. Helpful for the CountingGroupImpl.multiexp(Multiexponentiation) method.

Parameters:

count - true if we want to count the operation, false otherwise

op

public GroupElementImpl op(GroupElementImpl e)
                    throws java.lang.IllegalArgumentException

Description copied from interface: GroupElementImpl

Calculates the result of this op e.

Specified by:

op in interface GroupElementImpl

Parameters:

e - right hand side of the operation

Returns:

the element resulting from the group operation

Throws:

java.lang.IllegalArgumentException - if e is of the wrong type

pow

protected GroupElementImpl pow(java.math.BigInteger k,
                               boolean count)

Allows to configure whether to count this exponentiation. Helpful for the CountingGroupImpl.multiexp(Multiexponentiation) method.

Parameters:

k - exponent

count - true if we want to count the exponentiation, false otherwise

pow

public GroupElementImpl pow(java.math.BigInteger k)

Description copied from interface: GroupElementImpl

Calculates the result of applying the group operation k times.

Specified by:

pow in interface GroupElementImpl

isNeutralElement

public boolean isNeutralElement()

Description copied from interface: GroupElementImpl

Returns true iff this is the neutral element of the group.

Specified by:

isNeutralElement in interface GroupElementImpl

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

updateAccumulator

public ByteAccumulator updateAccumulator(ByteAccumulator accumulator)

Description copied from interface: UniqueByteRepresentable

Updates the ByteAccumulator with the unique byte representation of this object.

The input to the accumulators update function is an injective (with respect to a given domain) byte encoding of this object.

For many use-cases, the AnnotatedUbrUtil can be used to quickly implement this method.

Specified by:

updateAccumulator in interface UniqueByteRepresentable

Returns:

the same accumulator as was input

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 o)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object