Twofish (cipher)

From Citizendium
Jump to navigation Jump to search
The printable version is no longer supported and may have rendering errors. Please update your browser bookmarks and please use the default browser print function instead.
This article may be deleted soon.
To oppose or discuss a nomination, please go to CZ:Proposed for deletion and follow the instructions.

For the monthly nomination lists, see
Category:Articles for deletion.


This article is developing and not approved.
Main Article
Discussion
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
 
This editable Main Article is under development and subject to a disclaimer.

Twofish [1] is a block cipher from Bruce Schneier's company Counterpane. It was designed as a candidate cipher for the AES competition, and was a finalist though not the winner. Like all candidates, it uses 128-bit blocks and supports key sizes of 128, 192 or 256 bits. It is a 16-round Feistel cipher using four key-dependent 8*8 S-boxes.

Except for the name, and using key-dependent S-boxes, it has little relationship to Blowfish; Twofish was a new design. It uses the pseudo-Hadamard transform in the round function. It has a successor named "Threefish", used in the Skein hash algorithm, a candidate in the Advanced Hash Standard contest. That is another new design.

The cipher is freely available for any use. It has a home page.

References

  1. Bruce Schneier, John Kelsey, Doug Whiting, David Wagner, Chris Hall, Niels Ferguson (1998), Twofish: A 128-Bit Block Cipher