In
cryptography, 3-Way is a
block cipher
In cryptography, a block cipher is a deterministic algorithm operating on fixed-length groups of bits, called ''blocks''. Block ciphers are specified cryptographic primitive, elementary components in the design of many cryptographic protocols and ...
designed in 1994 by
Joan Daemen. It is closely related to
BaseKing; 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 represented a ...
s, notably not a
power of two such as the more common 64 or 128 bits. The
key length is also 96 bits. The figure 96 arises from the use of three 32 bit
words in the algorithm, from which also is derived the
cipher
In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure. An alternative, less common term is ''encipherment''. To encipher or encode i ...
'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
In cryptography, an SP-network, or substitution–permutation network (SPN), is a series of linked mathematical operations used in block cipher algorithms such as AES (Rijndael), 3-Way, Kalyna, Kuznyechik, PRESENT, SAFER, SHARK, and Square.
S ...
.
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
Cryptanalysis (from the Greek ''kryptós'', "hidden", and ''analýein'', "to analyze") refers to the process of analyzing information systems in order to understand hidden aspects of the systems. Cryptanalysis is used to breach cryptographic sec ...
.
John Kelsey,
Bruce Schneier, and
David Wagner showed how it can be broken with one related key query and about
chosen plaintexts.
References
*
*
External links
SCAN's entry for 3-WayChapter 7 of Daemen's thesis(
gzipped Postscript)
{{Cryptography navbox , block
Broken block ciphers