FACTOID # 22: South Dakota has the highest employment ratio in America, but the lowest median earnings of full-time male employees.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Crab (cipher)
Crab
Designer(s): Burt Kaliski,
Matt Robshaw
First published: 1993
Derived from: MD5
Key size(s): 80 bits
Block size(s): 8192 bits

In cryptography, Crab is a block cipher created by Burt Kaliski and Matt Robshaw in 1993. Not really intended for use, Crab was developed to demonstrate how ideas from hash functions could be used to create a fast cipher. In cryptography, MD5 (Message-Digest algorithm 5) is a widely used cryptographic hash function with a 128-bit hash value. ... In cryptography, the key size (alternatively key length) is a measure of the number of possible keys which can be used in a cipher. ... In modern cryptography, symmetric key ciphers are generally divided into stream ciphers and block ciphers. ... The German Lorenz cipher machine, used in World War II for encryption of very high-level general staff messages Cryptography (or cryptology; derived from Greek κρυπτός kryptós hidden, and γράφειν gráfein to write) is the study of message secrecy. ... Encryption Decryption In cryptography, a block cipher is a symmetric key cipher which operates on fixed-length groups of bits, termed blocks, with an unvarying transformation. ... In cryptography, a cryptographic hash function is a hash function with certain additional security properties to make it suitable for use as a primitive in various information security applications, such as authentication and message integrity. ...


Crab has an unusually large block size of 8192 bits. Its creators suggested using an 80-bit key, but the cipher could use any key size. The key is used to generate two large sets of subkeys: a permutation of the numbers 0 through 255, and an array of 2048 32-bit numbers. The block is divided into 256 32-bit subblocks, which are permuted at the beginning. Then the algorithm makes four passes over the data, each time applying one of four transformations adapted from MD5. In cryptography, the key size (alternatively key length) is a measure of the number of possible keys which can be used in a cipher. ... The key-schedule of DES In cryptography, the algorithm for computing the subkeys for each round in a product cipher from the encryption (or decryption) key is called the key schedule. ... In cryptography, MD5 (Message-Digest algorithm 5) is a widely used cryptographic hash function with a 128-bit hash value. ...


References

  • Schneier, Bruce. Applied Cryptography, 2nd edition, 1996. ISBN 0-471-11709-9.
edit
Block ciphers
Algorithms: 3-Way | AES | Akelarre | Anubis | Blowfish | C2 | Camellia | CAST-128 | CAST-256 | Cobra | CMEA | Crab | CS-Cipher | DEAL | DES | DES-X | DFC | FEAL | FROG | G-DES | GOST | Hasty Pudding Cipher | ICE | IDEA | IDEA NXT | Iraqi | KASUMI | KHAZAD | Khufu and Khafre | Libelle | LOKI89/91 | LOKI97 | Lucifer | MacGuffin | Madryga | MAGENTA | MARS | Mercy | MESH | MISTY1 | MMB | MULTI2 | NewDES | NOEKEON | NUSH | Q | RC2 | RC5 | RC6 | REDOC | Red Pike | S-1 | SAFER | SC2000 | SEED | Serpent | SHACAL | SHARK | Skipjack | SMS4 | Square | TEA | Triple DES | Twofish | XTEA
Design: Feistel network | Key schedule | Product cipher | S-box | SPN   Attacks: Brute force | Linear / Differential cryptanalysis | Mod n | Related key | XSL
Standardization: AES process | CRYPTREC | NESSIE   Misc: Avalanche effect | Block size | IV | Key size | Modes of operation | Piling-up lemma | Weak key
edit
Cryptography
History of cryptography | Cryptanalysis | Cryptography portal | Topics in cryptography
Symmetric-key algorithm | Block cipher | Stream cipher | Public-key cryptography | Cryptographic hash function | Message authentication code | Random numbers

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m