public class Serpent extends BaseCipher
Serpent is a 32-round substitution-permutation network block cipher, operating on 128-bit blocks and accepting keys of 128, 192, and 256 bits in length. At each round the plaintext is XORed with a 128 bit portion of the session key -- a 4224 bit key computed from the input key -- then one of eight S-boxes are applied, and finally a simple linear transformation is done. Decryption does the exact same thing in reverse order, and using the eight inverses of the S-boxes.
Serpent was designed by Ross Anderson, Eli Biham, and Lars Knudsen as a proposed cipher for the Advanced Encryption Standard.
Serpent can be sped up greatly by replacing S-box substitution with a sequence of binary operations, and the optimal implementation depends upon finding the fastest sequence of binary operations that reproduce this substitution. This implementation uses the S-boxes discovered by Dag Arne Osvik, which are optimized for the Pentium family of processors.
References:
currentBlockSize, currentKey, defaultBlockSize, defaultKeySize, lock, name
CIPHER_BLOCK_SIZE, KEY_MATERIAL
Constructor and Description |
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Serpent()
Trivial zero-argument constructor.
|
Modifier and Type | Method and Description |
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java.util.Iterator |
blockSizes()
Returns an
Iterator over the supported block sizes. |
java.lang.Object |
clone()
Returns a clone of this instance.
|
void |
decrypt(byte[] in,
int i,
byte[] out,
int o,
java.lang.Object K,
int bs) |
void |
encrypt(byte[] in,
int i,
byte[] out,
int o,
java.lang.Object K,
int bs) |
java.util.Iterator |
keySizes()
Returns an
Iterator over the supported key sizes. |
java.lang.Object |
makeKey(byte[] kb,
int blockSize) |
boolean |
selfTest()
A correctness test that consists of basic symmetric encryption /
decryption test(s) for all supported block and key sizes, as well as one
(1) variable key Known Answer Test (KAT).
|
currentBlockSize, decryptBlock, defaultBlockSize, defaultKeySize, encryptBlock, init, name, reset, testKat, testKat
public java.lang.Object clone()
IBlockCipher
Returns a clone of this instance.
clone
in interface IBlockCipher
clone
in class BaseCipher
public java.util.Iterator blockSizes()
IBlockCipher
Returns an Iterator
over the supported block sizes. Each
element returned by this object is an Integer
.
Iterator
over the supported block sizes.public java.util.Iterator keySizes()
IBlockCipher
Returns an Iterator
over the supported key sizes. Each element
returned by this object is an Integer
.
Iterator
over the supported key sizes.public java.lang.Object makeKey(byte[] kb, int blockSize) throws java.security.InvalidKeyException
java.security.InvalidKeyException
public void encrypt(byte[] in, int i, byte[] out, int o, java.lang.Object K, int bs)
public void decrypt(byte[] in, int i, byte[] out, int o, java.lang.Object K, int bs)
public boolean selfTest()
IBlockCipher
A correctness test that consists of basic symmetric encryption / decryption test(s) for all supported block and key sizes, as well as one (1) variable key Known Answer Test (KAT).
selfTest
in interface IBlockCipher
selfTest
in class BaseCipher
true
if the implementation passes simple
correctness tests. Returns false
otherwise.Copyright © 2025. All rights reserved.