de.flexiprovider.pqc.pflash
Class PFlashSignature

java.lang.Object
  |
  +--java.security.SignatureSpi
        |
        +--de.flexiprovider.api.Signature
              |
              +--de.flexiprovider.pqc.pflash.PFlashSignature

public class PFlashSignature

extends Signature

This class implements the pFLASH signature scheme. It only works when the parameters are set to
q = 16, n = 96, α = r = 32, s = 1.

With these values the length of the hash of the message, that should be signed, must be 256 bits. For that reason we chose SHA-256 as the message digest.

The PFlashSignature can be used as follow:

Signature generation

1. get instance of PFlashSignature Signature pflashSig = Registry.getSignature("pFLASH");
2. initialize signing
   pflashSig.initSign(privateKey, secureRandom);
3. sign message
   pflashSig.update(message.getBytes());
   byte[] signature = pflashSign.sign();

Signature verification

1. initialize verifying
   pflashSign.initVerify(publicKey);
2. verify the signature
   pflashSign.update(message.getBytes());
   boolean accepted = pflashSign.verify(signature);

Author:

Marian Hornschuch, Alexander Koller

See Also:

PFlashKeyPairGenerator

Field Summary

static java.lang.String

OID OID of the algorithm

Fields inherited from class java.security.SignatureSpi

appRandom

Constructor Summary

PFlashSignature()
pFLASH Signature with SHA256

Method Summary

void	initSign(PrivateKey key, SecureRandom srandom) Initialize the signature algorithm for signing a message.
void	initVerify(PublicKey key) Initialize the signature algorithm for verifying a signature.
void	setParameters(AlgorithmParameterSpec params) Initialize this signature engine with specified parameter set (Not used)
byte[]	sign() Sign a message.
void	update(byte input) Feed a message byte to the message digest.
void	update(byte[] input, int inOff, int inLen) Feed an array of message bytes to the message digest.
boolean	verify(byte[] sigBytes) Verfify a signature.

Methods inherited from class de.flexiprovider.api.Signature

engineGetParameter, engineInitSign, engineInitSign, engineInitVerify, engineSetParameter, engineSetParameter, engineSign, engineUpdate, engineUpdate, engineVerify, engineVerify, initSign, sign, update, verify, verify, verify

Methods inherited from class java.security.SignatureSpi

clone, engineSign

Methods inherited from class java.lang.Object

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

Field Detail

OID

public static final java.lang.String OID

OID of the algorithm

Constructor Detail

PFlashSignature

public PFlashSignature()

pFLASH Signature with SHA256

The default values for the parameters are :

degree of extension m	=	4
field polynomial of GF(2m)	=	X4 + X + 1
extension degree of E/K	=	96
α	=	32
r	=	32
s	=	1

Method Detail

initSign

public void initSign(PrivateKey key,
                     SecureRandom srandom)
              throws InvalidKeyException

Initialize the signature algorithm for signing a message.

Overrides:

initSign in class Signature

Parameters:

key - the private key of the signer

srandom - a source of randomness

Throws:

InvalidKeyException - if the key is not an instance of PFlashPrivateKey

initVerify

public void initVerify(PublicKey key)
                throws InvalidKeyException

Initialize the signature algorithm for verifying a signature.

Overrides:

initVerify in class Signature

Parameters:

key - the public key of the signer

Throws:

InvalidKeyException - if the public key is not an instance of PFlashPublicKey

setParameters

public void setParameters(AlgorithmParameterSpec params)

Initialize this signature engine with specified parameter set (Not used)

Overrides:

setParameters in class Signature

Parameters:

params - the parameters (not used)

update

public void update(byte input)

Feed a message byte to the message digest.

Overrides:

update in class Signature

Parameters:

input - the message byte

update

public void update(byte[] input,
                   int inOff,
                   int inLen)

Feed an array of message bytes to the message digest.

Overrides:

update in class Signature

Parameters:

input - array of message bytes

inOff - index of message start

inLen - number of message bytes

sign

public byte[] sign()

Sign a message.

Overrides:

sign in class Signature

Returns:

the signature

verify

public boolean verify(byte[] sigBytes)

Verfify a signature.

Overrides:

verify in class Signature

Parameters:

signature - the signature to be verified

Returns:

true if signature is valid, false otherwise