SYNOPSIS

use Crypt::Twofish;

$cipher = Crypt::Twofish->new($key);

$ciphertext = $cipher->encrypt($plaintext);

$plaintext = $cipher->decrypt($ciphertext);

DESCRIPTION

Twofish is a 128-bit symmetric block cipher with a variable length (128, 192, or 256-bit) key, developed by Counterpane Labs. It is unpatented and free for all uses, as described at <URL:http://www.counterpane.com/twofish.html>.

This module implements Twofish encryption. It supports the Crypt::CBC interface, with the functions described below. It also provides an interface that is call-compatible with Crypt::Twofish 1.0, but its use in new code is strongly discouraged.

Functions

blocksize

Returns the size (in bytes) of the block (16, in this case).

keysize

Returns the size (in bytes) of the key. Although the module understands 128, 192, and 256-bit keys, it returns 16 for compatibility with Crypt::CBC.

new($key)

This creates a new Crypt::Twofish object with the specified key (which should be 16, 24, or 32 bytes long).

encrypt($data)

Encrypts blocksize() bytes of $data and returns the corresponding ciphertext.

decrypt($data)

Decrypts blocksize() bytes of $data and returns the corresponding plaintext.

ACKNOWLEDGEMENTS

Nishant Kakani

For writing Crypt::Twofish 1.0 (this version is a complete rewrite).

Tony Cook

For making the module work under Activeperl, testing on several platforms, and suggesting that I probe for features via %Config.

AUTHOR

Abhijit Menon-Sen <[email protected]>

Copyright 2001 Abhijit Menon-Sen.

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.