Search results
Results from the WOW.Com Content Network
The cipher feedback (CFB) mode, in its simplest form uses the entire output of the block cipher. In this variation, it is very similar to CBC, turning a block cipher into a self-synchronizing stream cipher. CFB decryption in this variation is almost identical to CBC encryption performed in reverse:
RC5 is a block cipher designed by Ronald Rivest in 1994 which, unlike many other ciphers, has a variable block size (32, 64, or 128 bits), key size (0 to 2040 bits), and a number of rounds (0 to 255). The original suggested choice of parameters was a block size of 64 bits, a 128-bit key, and 12 rounds.
In cryptography, residual block termination is a variation of cipher block chaining mode (CBC) that does not require any padding. It does this by effectively changing to cipher feedback mode for one block. The cost is the increased complexity.
In cryptography, F-FCSR is a stream cipher developed by Thierry Berger, François Arnault, and Cédric Lauradoux. The core of the cipher is a Feedback with Carry Shift Register (FCSR) automaton, which is similar to a LFSR, but they perform operations with carries so their transition function is nonlinear.
ISO/IEC 10116 Information technology — Security techniques — Modes of operation for an n-bit block cipher [1] is an international standard that specifies modes of operation for block ciphers of any length. The modes defined are: Electronic codebook (ECB) Cipher block chaining (CBC) Cipher feedback (CFB) Output feedback (OFB) Counter (CTR)
Important LFSR-based stream ciphers include A5/1 and A5/2, used in GSM cell phones, E0, used in Bluetooth, and the shrinking generator. The A5/2 cipher has been broken and both A5/1 and E0 have serious weaknesses. [14] [15] The linear feedback shift register has a strong relationship to linear congruential generators. [16]
Nonlinear-feedback shift registers are components in modern stream ciphers, especially in RFID and smartcard applications. NLFSRs are known to be more resistant to cryptanalytic attacks than Linear Feedback Shift Registers .
In sequence design, a Feedback with Carry Shift Register (or FCSR) is the arithmetic or with carry analog of a linear-feedback shift register (LFSR). If > is an integer, then an N-ary FCSR of length is a finite state device with a state (;) = (,, …,;) consisting of a vector of elements in {,, …,} = and an integer .