cryptography Cryptography, or cryptology (from grc, , translit=kryptós "hidden, secret"; and ''graphein'', "to write", or ''-logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of adver ...

, 3-Way is a block cipher designed in 1994 by

Joan Daemen Joan Daemen (; born 1965) is a Belgian cryptographer who co-designed with Vincent Rijmen the Rijndael cipher, which was selected as the Advanced Encryption Standard (AES) in 2001. More recently, he co-designed the Keccak cryptographic hash, w ...

. It is closely related to

BaseKing In cryptography, BaseKing is a block cipher designed in 1994 by Joan Daemen. It is very closely related to 3-Way, as the two are variants of the same general cipher technique. BaseKing has a block size of 192 bits–twice as long as 3-Way, ...

; the two are variants of the same general cipher technique. 3-Way has a block size of 96

bit The bit is the most basic unit of information in computing and digital communications. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represente ...

s, notably not a

power of two A power of two is a number of the form where is an integer, that is, the result of exponentiation with number two as the base and integer as the exponent. In a context where only integers are considered, is restricted to non-negativ ...

such as the more common 64 or 128 bits. The

key length In cryptography, key size, key length, or key space refer to the number of bits in a key used by a cryptographic algorithm (such as a cipher). Key length defines the upper-bound on an algorithm's security (i.e. a logarithmic measure of the faste ...

is also 96 bits. The figure 96 arises from the use of three 32 bit

word A word is a basic element of language that carries an objective or practical meaning, can be used on its own, and is uninterruptible. Despite the fact that language speakers often have an intuitive grasp of what a word is, there is no conse ...

s in the algorithm, from which also is derived the cipher's name. When 3-Way was invented, 96-bit keys and blocks were quite strong, but more recent ciphers have a 128-bit block, and few now have keys shorter than 128 bits. 3-Way is an 11-round substitution–permutation network. 3-Way is designed to be very efficient in a wide range of platforms from 8-bit processors to specialized hardware, and has some elegant mathematical features which enable nearly all the decryption to be done in exactly the same circuits as did the encryption. 3-Way, just as its counterpart BaseKing, is vulnerable to related key cryptanalysis. John Kelsey,

Bruce Schneier Bruce Schneier (; born January 15, 1963) is an American cryptographer, computer security professional, privacy specialist, and writer. Schneier is a Lecturer in Public Policy at the Harvard Kennedy School and a Fellow at the Berkman Klein Cente ...

, and David Wagner showed how it can be broken with one related key query and about

2^

chosen plaintexts.

References

* *

External links

SCAN's entry for 3-Way

Chapter 7 of Daemen's thesis
(

gzip gzip is a file format and a software application used for file compression and decompression. The program was created by Jean-loup Gailly and Mark Adler as a free software replacement for the compress program used in early Unix systems, and i ...

ped Postscript) {{Cryptography navbox , block Broken block ciphers