NAME

Crypt::Twofish - The Twofish Encryption Algorithm

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 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.

SEE ALSO

Crypt::CBC, Crypt::Blowfish, Crypt::TEA

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 <ams@toroid.org>

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.