Package edu.fiu.adwise.homomorphic_encryption.elgamal

Class ElGamalSignature

java.lang.Object

edu.fiu.adwise.homomorphic_encryption.elgamal.ElGamalSignature

All Implemented Interfaces:

CipherConstants

public class ElGamalSignature
extends Object
implements CipherConstants

This class provides methods for signing and verifying messages using the ElGamal signature scheme.

The ElGamal signature scheme is a cryptographic algorithm used for digital signatures. For more details, see ElGamal Signature Scheme.

Field Summary

Fields inherited from interface edu.fiu.adwise.homomorphic_encryption.misc.CipherConstants

BILLION, CERTAINTY, EIGHT, FIELD_SIZE, FIVE, FOUR, KEY_SIZE, NEG_ONE, rnd, THREE, TWO

Constructor Summary

Constructors

Constructor	Description
ElGamalSignature()

Method Summary

Modifier and Type	Method	Description
static ElGamal_Ciphertext	sign(BigInteger message, ElGamalPrivateKey private_key)	Signs a message using the ElGamal private key.
static boolean	verify(BigInteger message, ElGamal_Ciphertext signature, ElGamalPublicKey public_key)	Verifies a signed message using the ElGamal public key.

Methods inherited from class java.lang.Object

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

Constructor Details

ElGamalSignature

public ElGamalSignature()

Method Details

sign

public static ElGamal_Ciphertext sign(BigInteger message,
 ElGamalPrivateKey private_key)

Signs a message using the ElGamal private key.

This method generates a digital signature for the given message using the private key.

Parameters:

message - The plaintext message to be signed.

private_key - The ElGamal private key used for signing.

Returns:

An ElGamal_Ciphertext object containing the signature (r, s).

verify

public static boolean verify(BigInteger message,
 ElGamal_Ciphertext signature,
 ElGamalPublicKey public_key)

Verifies a signed message using the ElGamal public key.

This method checks the integrity and authenticity of the signed message.

Parameters:

message - The plaintext message to verify.

signature - The signed message to verify, represented as an ElGamal_Ciphertext.

public_key - The ElGamal public key used for verification.

Returns:

true if the signature is valid, false otherwise.