Package edu.fiu.adwise.homomorphic_encryption.gm

Class GMCipher

java.lang.Object

edu.fiu.adwise.homomorphic_encryption.gm.GMCipher

All Implemented Interfaces:

CipherConstants

public class GMCipher
extends Object
implements CipherConstants

This class implements the Goldwasser-Micali (GM) encryption scheme. It provides methods for encrypting, decrypting, and performing XOR operations on encrypted bits using the GM cryptosystem.

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
GMCipher()

Method Summary

Modifier and Type	Method	Description
static BigInteger	decrypt(BigInteger[] cipher, GMPrivateKey private_key)	Decrypts an array of Goldwasser-Micali encrypted bits.
static BigInteger[]	encrypt(BigInteger message, GMPublicKey public_key)	Encrypts a BigInteger plaintext using the Goldwasser-Micali encryption scheme.
static BigInteger[]	xor(BigInteger[] cipher_1, BigInteger[] cipher_2, GMPublicKey public_key)	Performs a bitwise XOR operation on two arrays of Goldwasser-Micali encrypted bits.

Methods inherited from class java.lang.Object

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

Constructor Details

GMCipher

public GMCipher()

Method Details

encrypt

public static BigInteger[] encrypt(BigInteger message,
 GMPublicKey public_key)

Encrypts a BigInteger plaintext using the Goldwasser-Micali encryption scheme.

Parameters:

message - The plaintext message to be encrypted.

public_key - The public key used for encryption.

Returns:

An array of BigInteger representing the encrypted bits.

decrypt

public static BigInteger decrypt(BigInteger[] cipher,
 GMPrivateKey private_key)

Decrypts an array of Goldwasser-Micali encrypted bits.

Parameters:

cipher - The array of encrypted bits to be decrypted.

private_key - The private key used for decryption.

Returns:

The decrypted plaintext as a BigInteger.

xor

public static BigInteger[] xor(BigInteger[] cipher_1,
 BigInteger[] cipher_2,
 GMPublicKey public_key)
                        throws HomomorphicException

Performs a bitwise XOR operation on two arrays of Goldwasser-Micali encrypted bits.

Parameters:

cipher_1 - The first array of encrypted bits.

cipher_2 - The second array of encrypted bits.

public_key - The public key used for encryption.

Returns:

An array of BigInteger representing the XORed encrypted bits.

Throws:

HomomorphicException - If the lengths of the two ciphertext arrays are not equal.