iaik.security.lw.ascon

Class AsconVarPrfASpi

java.lang.Object

javax.crypto.MacSpi

iaik.security.lw.ascon.AsconMacSpi

iaik.security.lw.ascon.AsconVarPrfASpi

public class AsconVarPrfASpi
extends AsconMacSpi

JCE Mac(Spi) implementation of the Ascon-Prfa algorithm.

Ascon-Prfa is parameterized by the key length (128-bit), output rate (128-bit), the internal round number (8-rounds), and the tag of variable length. Ascon message authentication modes use the same lightweight 320-bit permutation as the authenticated encryption modes.

The authentication algorithm takes as its input a 128-bit secret key and a message of arbitrary length. Further, the length of the tag is chosen by the user and passed to the PRF instance with the AsconParameterSpec. After each absorbed or squeezed block except the last, the intermediate 8-round permutation is applied to the state, processing the plaintext. For Ascon-Prf, an intermediate 12-round permutation is applied. The full 12-round permutation is applied for both Ascon-Prfa and Ascon-Prf during the initialization and finalization after the last message block. Finally, it produces a tag as its output. For more details we refer to the official Ascon specification.

Usage example:

 // register IAIK-LW provider
 IaikLw.addAsProvider();
 

 // the message to be processed
 byte[] msg = ...;
 

 // generate the secret key
 KeyGenerator keyGenerator = KeyGenerator.getInstance("Ascon-Mac");
 SecretKey key = keyGenerator.generateKey();
 

 // generate a AsconParameterSpec specifying the tag length
 int tagLength = ...;
 AsconParameterSpec parameterSpec = new AsconParameterSpec(tagLength);
 

 // generate the tag
 Mac prf = Mac.getInstance("Ascon-Prf");
 prf.init(secretKey, parameterSpec);
 prf.update(msg);
 byte[] result = mac.doFinal();
 

See Also:

AsconVarPrfSpi, AsconParameterSpec, Ascon128CipherSpi

Constructor Summary

Constructors

Constructor and Description
AsconVarPrfASpi()

Method Summary

Modifier and Type	Method and Description
protected int	getRate() Gets the block rate for the variant in bytes.
protected String	getVariant() Gets the variant name.

Methods inherited from class iaik.security.lw.ascon.AsconMacSpi

engineDoFinal, engineGetMacLength, engineInit, engineReset, engineUpdate, engineUpdate

Methods inherited from class javax.crypto.MacSpi

clone, engineUpdate

Methods inherited from class java.lang.Object

equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AsconVarPrfASpi

public AsconVarPrfASpi()

Method Detail

getVariant

protected String getVariant()

Gets the variant name.

Specified by:

getVariant in class AsconMacSpi

Returns:

Ascon-Prfa

getRate

protected int getRate()

Gets the block rate for the variant in bytes.

Specified by:

getRate in class AsconMacSpi

Returns:

40 (bytes)