org.cryptimeleon.math.prf.aes

Class AesPseudorandomFunction

java.lang.Object

org.cryptimeleon.math.prf.aes.AesPseudorandomFunction

All Implemented Interfaces:

PseudorandomFunction, RepresentationRestorer, Representable, StandaloneRepresentable

public class AesPseudorandomFunction
extends java.lang.Object
implements PseudorandomFunction

AES as a pseudorandom function (permutation) \(f_k : \{0,1\}^l \rightarrow \{0,1\}^l\) for \(k \in \{0,1\}^l\). Here, l is any valid AES keylength (e.g., 128, 256).

PrfKey, PrfPreimage, and PrfImage are of type ByteArrayImpl.

Field Summary

Fields

Modifier and Type	Field and Description
protected java.lang.Integer	keylength

Constructor Summary

Constructors

Constructor and Description
AesPseudorandomFunction(int keylength) Instantiates the PRF with a given AES key length.
AesPseudorandomFunction(Representation repr)

Method Summary

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

Field Detail

keylength

protected java.lang.Integer keylength

Constructor Detail

AesPseudorandomFunction

public AesPseudorandomFunction(int keylength)

Instantiates the PRF with a given AES key length.

Parameters:

keylength - a valid AES key length in bit (e.g., 128 or 256)

AesPseudorandomFunction

public AesPseudorandomFunction(Representation repr)

Method Detail

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

generateKey

public PrfKey generateKey()

Description copied from interface: PseudorandomFunction

Generates a key k for use with this PRF.

Specified by:

generateKey in interface PseudorandomFunction

evaluate

public PrfImage 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 PrfKey restoreKey(Representation repr)

Description copied from interface: PseudorandomFunction

Restores a key k from its representation.

Specified by:

restoreKey in interface PseudorandomFunction

restorePreimage

public PrfPreimage restorePreimage(Representation repr)

Description copied from interface: PseudorandomFunction

Restores a preimage x from its representation.

Specified by:

restorePreimage in interface PseudorandomFunction

restoreImage

public PrfImage restoreImage(Representation repr)

Description copied from interface: PseudorandomFunction

Restores an image y from its representation.

Specified by:

restoreImage in interface PseudorandomFunction

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

getKeylength

public java.lang.Integer getKeylength()