Package edu.fiu.adwise.homomorphic_encryption.paillier

Class PaillierPublicKey

java.lang.Object

edu.fiu.adwise.homomorphic_encryption.paillier.PaillierPublicKey

All Implemented Interfaces:

PaillierKey, Serializable, Key, PublicKey

public final class PaillierPublicKey
extends Object
implements Serializable, PaillierKey, PublicKey

Represents the public key for the Paillier cryptosystem. This class implements the Serializable, Paillier_Key, PublicKey, Runnable, and CipherConstants interfaces. It provides methods for key generation and serialization for encryption operations.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
final int	key_size	The size of the key in bits.

Constructor Summary

Constructors

Constructor	Description
PaillierPublicKey(int key_size, BigInteger n, BigInteger modulus, BigInteger g)	Constructs a Paillier public key with the specified parameters.

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object o)	Compares this public key with another object for equality.
String	getAlgorithm()	Returns the algorithm name for this key.
byte[]	getEncoded()	Returns the encoded form of the key.
String	getFormat()	Returns the format of the key encoding.
BigInteger	getModulus()	Retrieves the modulus used in the Paillier cryptosystem.
BigInteger	getN()	Retrieves the value of n, which is part of the Paillier key.
static PaillierPublicKey	readKey(String paillier_public_key)	Reads a public key from a file.
String	toString()	Returns a string representation of the public key.
void	writeKey(String paillier_public_key_file)	Writes the public key to a file.
BigInteger	ZERO()	Retrieves the encryption of zero using this public key.

Methods inherited from class java.lang.Object

getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Details

key_size

public final int key_size

The size of the key in bits.

Constructor Details

PaillierPublicKey

public PaillierPublicKey(int key_size,
 BigInteger n,
 BigInteger modulus,
 BigInteger g)

Constructs a Paillier public key with the specified parameters.

Parameters:

key_size - The size of the key in bits.

n - The value of n (product of two primes p and q).

modulus - The modulus (n^2).

g - The generator g.

Method Details

ZERO

public BigInteger ZERO()
                throws HomomorphicException

Retrieves the encryption of zero using this public key.

Returns:

The encryption of zero as a BigInteger.

Throws:

HomomorphicException - If an error occurs during encryption.

toString

public String toString()

Returns a string representation of the public key.

Overrides:

toString in class Object

Returns:

A string representation of the public key.

writeKey

public void writeKey(String paillier_public_key_file)
              throws IOException

Writes the public key to a file.

Parameters:

paillier_public_key_file - The file path to save the public key.

Throws:

IOException - If an I/O error occurs.

readKey

public static PaillierPublicKey readKey(String paillier_public_key)
                                 throws IOException,
ClassNotFoundException

Reads a public key from a file.

Parameters:

paillier_public_key - The file path to read the public key from.

Returns:

The PaillierPublicKey object.

Throws:

IOException - If an I/O error occurs.

ClassNotFoundException - If the class of the serialized object cannot be found.

getN

public BigInteger getN()

Retrieves the value of n, which is part of the Paillier key.

Specified by:

getN in interface PaillierKey

Returns:

The value of n as a BigInteger.

getModulus

public BigInteger getModulus()

Retrieves the modulus used in the Paillier cryptosystem.

Specified by:

getModulus in interface PaillierKey

Returns:

The modulus as a BigInteger.

getAlgorithm

public String getAlgorithm()

Returns the algorithm name for this key.

Specified by:

getAlgorithm in interface Key

Returns:

The algorithm name ("Paillier").

getFormat

public String getFormat()

Returns the format of the key encoding.

Specified by:

getFormat in interface Key

Returns:

The format ("X.509").

getEncoded

public byte[] getEncoded()

Returns the encoded form of the key.

Specified by:

getEncoded in interface Key

Returns:

The encoded key as a byte array, or null if not supported.

equals

public boolean equals(Object o)

Compares this public key with another object for equality.

Overrides:

equals in class Object

Parameters:

o - The object to compare with.

Returns:

True if the objects are equal, false otherwise.