org.cryptimeleon.math.prf.aes

Class LongAesPseudoRandomFunction

java.lang.Object

org.cryptimeleon.math.prf.aes.LongAesPseudoRandomFunction

All Implemented Interfaces:

PseudorandomFunction, RepresentationRestorer, Representable, StandaloneRepresentable

public class LongAesPseudoRandomFunction
extends java.lang.Object
implements PseudorandomFunction

AES based PRF with k key length and output length of the underlying AES key length. PRF_k(x) = AES_k1(x)||AES_k2(x)|..." with key k=(k1,k2,...)

This is basically a wrapper around AesPseudorandomFunction.

Constructor Summary

Constructors

Constructor and Description
LongAesPseudoRandomFunction(AesPseudorandomFunction aesPseudorandomFunction, int k) Instantiates the PRF with an AES instance and desired factor.
LongAesPseudoRandomFunction(Representation repr)

Method Summary

Modifier and Type	Method and Description
boolean	equals(java.lang.Object o)
ByteArrayImpl	evaluate(PrfKey k, PrfPreimage x) Maps a preimage x to its image using key k.
ByteArrayImpl	generateKey() Generates a key k for use with this PRF.
int	getKeyLengthBytes()
int	getPreimageLengthBytes()
Representation	getRepresentation() The representation of this object.
int	hashCode()
ByteArrayImpl	restoreImage(Representation repr) Restores an image y from its representation.
ByteArrayImpl	restoreKey(Representation repr) Restores a key k from its representation.
ByteArrayImpl	restorePreimage(Representation repr) Restores a preimage x from its representation.

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.cryptimeleon.math.prf.PseudorandomFunction

restoreFromRepresentation

Constructor Detail

LongAesPseudoRandomFunction

public LongAesPseudoRandomFunction(AesPseudorandomFunction aesPseudorandomFunction,
                                   int k)

Instantiates the PRF with an AES instance and desired factor.

Parameters:

k - factor by which output and key size of AES is increased

aesPseudorandomFunction - AES instance to use k times

LongAesPseudoRandomFunction

public LongAesPseudoRandomFunction(Representation repr)

Method Detail

generateKey

public ByteArrayImpl generateKey()

Description copied from interface: PseudorandomFunction

Generates a key k for use with this PRF.

Specified by:

generateKey in interface PseudorandomFunction

evaluate

public ByteArrayImpl evaluate(PrfKey k,
                              PrfPreimage x)

Description copied from interface: PseudorandomFunction

Maps a preimage x to its image using key k.

Specified by:

evaluate in interface PseudorandomFunction

Returns:

output of \(f_k(x)\)

restoreKey

public ByteArrayImpl restoreKey(Representation repr)

Description copied from interface: PseudorandomFunction

Restores a key k from its representation.

Specified by:

restoreKey in interface PseudorandomFunction

restorePreimage

public ByteArrayImpl restorePreimage(Representation repr)

Description copied from interface: PseudorandomFunction

Restores a preimage x from its representation.

Specified by:

restorePreimage in interface PseudorandomFunction

restoreImage

public ByteArrayImpl restoreImage(Representation repr)

Description copied from interface: PseudorandomFunction

Restores an image y from its representation.

Specified by:

restoreImage in interface PseudorandomFunction

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

getPreimageLengthBytes

public int getPreimageLengthBytes()

getKeyLengthBytes

public int getKeyLengthBytes()

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