gnu.crypto.mode
Class CTR
- Cloneable, IBlockCipher, IMode
public class CTR
implements Cloneable
The implementation of the Counter Mode.
The algorithm steps are formally described as follows:
CTR Encryption: O[j] = E(K)(T[j]); for j = 1, 2...n;
C[j] = P[j] ^ O[j]; for j = 1, 2...n.
CTR Decryption: O[j] = E(K)(T[j]); for j = 1, 2...n;
P[j] = C[j] ^ O[j]; for j = 1, 2...n.
where
P
is the plaintext,
C
is the ciphertext,
E(K)
is the underlying block cipher encryption function
parametrised with the session key
K
, and
T
is the
Counter.
This implementation, uses a standard incrementing function with a step of
1, and an initial value similar to that described in the NIST document.
References:
-
Recommendation for Block Cipher Modes of Operation Methods and Techniques,
Morris Dworkin.
CTR(IBlockCipher underlyingCipher, int cipherBlockSize) - Trivial package-private constructor for use by the Factory class.
|
blockSizes , clone , currentBlockSize , decryptBlock , defaultBlockSize , defaultKeySize , encryptBlock , init , keySizes , name , reset , selfTest , setup , teardown , update |
CTR
(package private) CTR(IBlockCipher underlyingCipher,
int cipherBlockSize)
Trivial package-private constructor for use by the Factory class.
underlyingCipher
- the underlying cipher implementation.cipherBlockSize
- the underlying cipher block size to use.
Copyright © 2001, 2002, 2003
Free Software Foundation,
Inc. All Rights Reserved.