public class CFB extends BaseMode
I[1] = IV I[j] = LSB(b-s, I[j-1]) | C[j-1] for j = 2...n O[j] = CIPH(K, I[j]) for j = 1,2...n C[j] = P[j] ^ MSB(s, O[j]) for j = 1,2...n
And decryption is:
I[1] = IV I[j] = LSB(b-s, I[j-1]) | C[j-1] for j = 2...n O[j] = CIPH(K, I[j]) for j = 1,2...n P[j] = C[j] ^ MSB(s, O[j]) for j = 1,2...n
CFB mode requires an initialization vector, which need not be kept secret.
References:
algorithmParams, cipher, cipherBlockSize, iv, lock, modeBlockSize, name, stateALGORITHM_PARAMS, DECRYPTION, ENCRYPTION, IV, MODE_BLOCK_SIZE, STATECIPHER_BLOCK_SIZE, KEY_MATERIAL| Modifier and Type | Method and Description |
|---|---|
java.lang.Object |
clone()
Returns a clone of this instance.
|
void |
decryptBlock(byte[] in,
int inOffset,
byte[] out,
int outOffset)
Decrypts exactly one block of ciphertext.
|
void |
encryptBlock(byte[] in,
int inOffset,
byte[] out,
int outOffset)
Encrypts exactly one block of plaintext.
|
void |
setup()
The initialisation phase of the concrete mode implementation.
|
void |
teardown()
The termination phase of the concrete mode implementation.
|
blockSizes, currentBlockSize, defaultBlockSize, defaultKeySize, init, keySizes, name, reset, selfTest, updatepublic java.lang.Object clone()
IBlockCipherReturns a clone of this instance.
clone in interface IBlockCipherclone in class BaseModepublic void setup()
BaseModepublic void teardown()
BaseModepublic void encryptBlock(byte[] in,
int inOffset,
byte[] out,
int outOffset)
IBlockCipherEncrypts exactly one block of plaintext.
encryptBlock in interface IBlockCipherencryptBlock in class BaseModein - the plaintext.inOffset - index of in from which to start considering
data.out - the ciphertext.outOffset - index of out from which to store result.public void decryptBlock(byte[] in,
int inOffset,
byte[] out,
int outOffset)
IBlockCipherDecrypts exactly one block of ciphertext.
decryptBlock in interface IBlockCipherdecryptBlock in class BaseModein - the plaintext.inOffset - index of in from which to start considering
data.out - the ciphertext.outOffset - index of out from which to store result.Copyright © 2025. All rights reserved.