What is MacGuffin (cipher)?
In [[cryptography]], '''MacGuffin''' is a [[block cipher]] created in 1994 by [[Bruce Schneier]] and [[Matt Blaze]] at a [[Fast Software Encryption|Fast Software Encryption workshop]]. It was intended as a [[Catalysis|catalyst]] for analysis of a new cipher structure, known as Generalized Unbalanced [[Feistel cipher|Feistel Networks]] (GUFNs). Schneier and Blaze based MacGuffin on [[Data Encryption Standard|DES]], their main change was spliting the DES [[Block size (cryptography)|64 bits]] data block into two unequal halves in the [[Feistel cipher|Feistel network]], 48 bits of the 64-bit data block are fed through the round function, whose output is [[XOR]]ed with the other 16 bits of the data block. MacGuffin's [[key schedule]] is a modified version of the [[encryption]] [[algorithm]] itself. Since MacGuffin is a Feistel network, decryption is easy; simply run the encryption algorithm in reverse. The algorithm was experimental, intended to explore the security properties of unbalanced Feistel networks. The [[cryptanalysis]] proceeded very quickly, so quickly that the cipher was broken using [[differential cryptanalysis]] at the same workshop by [[Vincent Rijmen]] and [[Bart Preneel]]. They also tried attacking MacGuffin with different [[Substitution box|S-boxes]], taken directly from DES. This version was slightly stronger. Rijmen and Preneel warn that designing an algorithm to resist only known attacks is generally not a good design principle. Schneier and Blaze recommended using 32 ''rounds'', and specified MacGuffin with a 128-bit key. ==References== * {{cite conference | author = Bruce Schneier, Matt Blaze | title = The MacGuffin Block Cipher Algorithm | book-title = 2nd International Workshop on [[Fast Software Encryption]] (FSE '94) | pages = 97–110 | publisher = [[Springer-Verlag]] | date = December 1994 | location = [[Leuven]] | url = http://www.schneier.com/paper-macguffin.html | format = [[PDF]]/[[PostScript]] | accessdate = 2007-08-24 }} * {{cite confe