- Crab (cipher)
Crab General Designers Burt Kaliski, Matt Robshaw First published 1993 Derived from MD5 Related to SHACAL Cipher detail Key sizes 80 bits Block sizes 8192 bits Structure Cryptographic hash function Best public cryptanalysis Proposed differential cryptanalysis using no more than 216 chosen plaintexts
In cryptography, Crab is a block cipher proposed by Burt Kaliski and Matt Robshaw at the first Fast Software Encryption workshop 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.
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 authors didn't specify an actual key schedule, only that 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.
A brief note on the cryptanalysis of Crab is included in Markku-Juhani Saarinen's paper on block ciphers based on SHA-1 and MD5, published at FSE 2003. The author demonstrates a weakness in Crab that permits a distinguisher using no more than a dozen chosen plaintexts, and speculates that this can be converted into a full key-recovery attack using no more than 216 chosen plaintexts. Such an attack would depend on the key schedule used.
- B.S. Kaliski and M.J.B. Robshaw (December 1993). "Fast Block Cipher Proposal". Fast Software Encryption (FSE '93). Cambridge: Springer-Verlag. pp. 33–40.
- U.S. Patent 6,463,150 A patent on an encryption device that uses Crab.
- Schneier, Bruce (1996). Applied Cryptography (2nd ed.). John Wiley & Sons. pp. 342–344. ISBN 0-471-11709-9.
- Markku-Juhani Olavi Saarinen (February 2003). "Cryptanalysis of Block Ciphers Based on SHA-1 and MD5" (PDF). FSE '03. Lund: Springer-Verlag. pp. 36–44. http://www.m-js.com/doc/saarinen_sha_md5.pdf. Retrieved 12 October 2007.
Block ciphers (security summary) Common
algorithms3-Way · ABC · Akelarre · Anubis · ARIA · BaseKing · BassOmatic · BATON · BEAR and LION · CAST-256 · CIKS-1 · CIPHERUNICORN-A · CIPHERUNICORN-E · CLEFIA · CMEA · Cobra · COCONUT98 · Crab · Cryptomeria/C2 · CRYPTON · CS-Cipher · DEAL · DES-X · DFC · E2 · FEAL · FEA-M · FROG · G-DES · GOST · Grand Cru · Hasty Pudding cipher · Hierocrypt · ICE · IDEA NXT · Intel Cascade Cipher · Iraqi · KASUMI · KeeLoq · KHAZAD · Khufu and Khafre · KN-Cipher · Ladder-DES · Libelle · LOKI97 · LOKI89/91 · Lucifer · M6 · M8 · MacGuffin · Madryga · MAGENTA · MARS · Mercy · MESH · MISTY1 · MMB · MULTI2 · MultiSwap · New Data Seal · NewDES · Nimbus · NOEKEON · NUSH · Q · RC6 · REDOC · Red Pike · S-1 · SAFER · SAVILLE · SC2000 · SHACAL · SHARK · SMS4 · Spectr-H64 · Square · SXAL/MBAL · Threefish · Treyfer · UES · Xenon · xmx · XXTEA · Zodiac
Standardization Misc Cryptography
Wikimedia Foundation. 2010.
Look at other dictionaries:
Crab (disambiguation) — A crab is a water dwelling creature, a decapod crustacean of the infraorder Brachyura. Crab may also refer to: Contents 1 Zoology 2 Food 3 Mythology … Wikipedia
Cipher security summary — This article summarizes publicly known attacks against ciphers. Note that not all entries may be up to date. Table color key No known successful attacks Theoretical break Attack demonstrated in practice The Best attack column lists the complexity … Wikipedia
Block cipher modes of operation — This article is about cryptography. For method of operating , see modus operandi. In cryptography, modes of operation is the procedure of enabling the repeated and secure use of a block cipher under a single key. A block cipher by itself… … Wikipedia
Block cipher — In cryptography, a block cipher is a symmetric key cipher operating on fixed length groups of bits, called blocks, with an unvarying transformation. A block cipher encryption algorithm might take (for example) a 128 bit block of plaintext as… … Wikipedia
Cryptomeria cipher — The Feistel function of the Cryptomeria cipher. General Designers 4C Entity First published … Wikipedia
Mercy (cipher) — This article is about the block cipher. For other uses, see Mercy (disambiguation). Mercy General Designers Paul Crowley First published April 2000 Derived from WAKE … Wikipedia
DFC (cipher) — This article is about the block cipher. For other uses, see DFC (disambiguation). DFC General Designers Jacques Stern, Serge Vaudenay, et al. First published 1998 Related to COCONUT98 Cipher detail … Wikipedia
Nimbus (cipher) — This article is about the block cipher. For other uses, see Nimbus (disambiguation). Nimbus General Designers Alexis Machado First published 2000 Cipher detail Key sizes 128 bits Block sizes … Wikipedia
Enigma (Maschine) — Markenschild der ENIGMA Die deutsche Schlüsselmaschine … Deutsch Wikipedia
Data Encryption Standard — The Feistel function (F function) of DES General Designers IBM First publis … Wikipedia