de.flexiprovider.pqc.hbc.ots
Class MerkleOTS

java.lang.Object
  |
  +--de.flexiprovider.pqc.hbc.ots.MerkleOTS

All Implemented Interfaces:

OTS

public class MerkleOTS

extends java.lang.Object

implements OTS

This class implements key pair generation and signature generation of the Merkle one-time signature scheme, described in R. Merkle, "A certified digital signature", LNCS 1462, pages 218–238, 1989. The class is used by the CMSS classes.

Author:

Elena Klintsevich

Constructor Summary

MerkleOTS()

Method Summary

boolean	canComputeVerificationKeyFromSignature() The verification key of come one-time signature schemes can be computes from the signature.
byte[]	computeVerificationKey(byte[] mBytes, byte[] sigBytes) Compute the OTS verification key from the one-time signature of a message.
void	generateKeyPair(byte[] seed) Generate an OTS key pair using the given seed and the message digest and PRNG specified via init(MessageDigest, PRNG).
void	generateSignatureKey(byte[] seed) Generate an OTS signature key the given seed and the message digest and PRNG specified via init(MessageDigest, PRNG).
void	generateVerificationKey() Generate an OTS verification key from the previously generated signature key given the message digest specified via init(MessageDigest, PRNG).
int	getSignatureLength()
byte[]	getVerificationKey()
int	getVerificationKeyLength()
void	init(MessageDigest md, PRNG rng) Initialize the OTS.
byte[]	sign(byte[] mBytes) Generate a one-time signature of the given message using the private key generated via generateKeyPair(byte[]).
boolean	verify(byte[] mBytes, byte[] sBytes, byte[] pBytes) Verify a one-time signature of the given message using the verification key generated via generateKeyPair(byte[]).

Methods inherited from class java.lang.Object

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

Constructor Detail

MerkleOTS

public MerkleOTS()

Method Detail

init

public void init(MessageDigest md,
                 PRNG rng)

Initialize the OTS.

Specified by:

init in interface OTS

Parameters:

md - the hash function for the OTS

rng - the name of the PRNG used for key pair generation

generateKeyPair

public void generateKeyPair(byte[] seed)

Generate an OTS key pair using the given seed and the message digest and PRNG specified via init(MessageDigest, PRNG).

Specified by:

generateKeyPair in interface OTS

Parameters:

seed - the seed for the PRGN

getVerificationKey

public byte[] getVerificationKey()

Specified by:

getVerificationKey in interface OTS

Returns:

The verification OTS key as one byte array

getSignatureLength

public int getSignatureLength()

Specified by:

getSignatureLength in interface OTS

Returns:

the length of the one-time signature

sign

public byte[] sign(byte[] mBytes)

Generate a one-time signature of the given message using the private key generated via generateKeyPair(byte[]).

Specified by:

sign in interface OTS

Parameters:

mBytes - the message

Returns:

the one-time signature of the message

computeVerificationKey

public byte[] computeVerificationKey(byte[] mBytes,
                                     byte[] sigBytes)

Compute the OTS verification key from the one-time signature of a message. This is *NOT* a complete OTS signature verification, but it suffices for usage with CMSS.

Specified by:

computeVerificationKey in interface OTS

Parameters:

mBytes - the message

sigBytes - the one-time signature

Returns:

the OTS verification key

canComputeVerificationKeyFromSignature

public boolean canComputeVerificationKeyFromSignature()

Description copied from interface: OTS

The verification key of come one-time signature schemes can be computes from the signature.

Specified by:

canComputeVerificationKeyFromSignature in interface OTS

Following copied from interface: de.flexiprovider.pqc.hbc.ots.OTS

Returns:

true if that is the case and false otherwise

generateSignatureKey

public void generateSignatureKey(byte[] seed)

Description copied from interface: OTS

Generate an OTS signature key the given seed and the message digest and PRNG specified via OTS.init(MessageDigest, PRNG).

Specified by:

generateSignatureKey in interface OTS

Following copied from interface: de.flexiprovider.pqc.hbc.ots.OTS

Parameters:

seed - the seed for the PRGN

generateVerificationKey

public void generateVerificationKey()

Description copied from interface: OTS

Generate an OTS verification key from the previously generated signature key given the message digest specified via OTS.init(MessageDigest, PRNG).

Specified by:

generateVerificationKey in interface OTS

getVerificationKeyLength

public int getVerificationKeyLength()

Specified by:

getVerificationKeyLength in interface OTS

Following copied from interface: de.flexiprovider.pqc.hbc.ots.OTS

Returns:

the length of the one-time verification key

verify

public boolean verify(byte[] mBytes,
                      byte[] sBytes,
                      byte[] pBytes)

Description copied from interface: OTS

Verify a one-time signature of the given message using the verification key generated via OTS.generateKeyPair(byte[]).

Specified by:

verify in interface OTS

Following copied from interface: de.flexiprovider.pqc.hbc.ots.OTS

Parameters:

mBytes - the message

sBytes - the signature

pBytes - the verification key

Returns:

true if signature is valid and false otherwise