org.spongycastle.pqc.crypto.mceliece

Class McElieceCipher

java.lang.Object

org.spongycastle.pqc.crypto.mceliece.McElieceCipher

All Implemented Interfaces:

MessageEncryptor

public class McElieceCipher
extends java.lang.Object
implements MessageEncryptor

This class implements the McEliece Public Key cryptosystem (McEliecePKCS). It was first described in R.J. McEliece, "A public key cryptosystem based on algebraic coding theory", DSN progress report, 42-44:114-116, 1978. The McEliecePKCS is the first cryptosystem which is based on error correcting codes. The trapdoor for the McEliece cryptosystem using Goppa codes is the knowledge of the Goppa polynomial used to generate the code.

Field Summary

Fields

Modifier and Type	Field and Description
int	cipherTextSize
int	maxPlainTextSize
static java.lang.String	OID The OID of the algorithm.

Constructor Summary

Constructors

Constructor and Description
McElieceCipher()

Method Summary

Modifier and Type	Method and Description
int	getKeySize(McElieceKeyParameters key) Return the key size of the given key object.
void	init(boolean forEncryption, CipherParameters param)
byte[]	messageDecrypt(byte[] input) Decrypt a cipher text.
byte[]	messageEncrypt(byte[] input) Encrypt a plain text.

Methods inherited from class java.lang.Object

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

Field Detail

OID

public static final java.lang.String OID

The OID of the algorithm.

See Also:

Constant Field Values

maxPlainTextSize

public int maxPlainTextSize

cipherTextSize

public int cipherTextSize

Constructor Detail

McElieceCipher

public McElieceCipher()

Method Detail

init

public void init(boolean forEncryption,
                 CipherParameters param)

Specified by:

init in interface MessageEncryptor

Parameters:

forEncryption - true if we are encrypting a signature, false otherwise.

param - key parameters for encryption or decryption.

getKeySize

public int getKeySize(McElieceKeyParameters key)

Return the key size of the given key object.

Parameters:

key - the McElieceKeyParameters object

Returns:

the keysize of the given key object

messageEncrypt

public byte[] messageEncrypt(byte[] input)

Encrypt a plain text.

Specified by:

messageEncrypt in interface MessageEncryptor

Parameters:

input - the plain text

Returns:

the cipher text

messageDecrypt

public byte[] messageDecrypt(byte[] input)
                      throws InvalidCipherTextException

Decrypt a cipher text.

Specified by:

messageDecrypt in interface MessageEncryptor

Parameters:

input - the cipher text

Returns:

the plain text

Throws:

java.lang.Exception - if the cipher text is invalid.

InvalidCipherTextException