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.IX Title "Twofish 3pm"
.TH Twofish 3pm 2024-01-10 "perl v5.38.2" "User Contributed Perl Documentation"
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.SH NAME
Crypt::Twofish \- The Twofish Encryption Algorithm
.SH SYNOPSIS
.IX Header "SYNOPSIS"
use Crypt::Twofish;
.PP
\&\f(CW$cipher\fR = Crypt::Twofish\->new($key);
.PP
\&\f(CW$ciphertext\fR = \f(CW$cipher\fR\->encrypt($plaintext);
.PP
\&\f(CW$plaintext\fR  = \f(CW$cipher\fR\->decrypt($ciphertext);
.SH DESCRIPTION
.IX Header "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>.
.PP
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.
.SS Functions
.IX Subsection "Functions"
.IP blocksize 4
.IX Item "blocksize"
Returns the size (in bytes) of the block (16, in this case).
.IP keysize 4
.IX Item "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.
.IP new($key) 4
.IX Item "new($key)"
This creates a new Crypt::Twofish object with the specified key (which
should be 16, 24, or 32 bytes long).
.IP encrypt($data) 4
.IX Item "encrypt($data)"
Encrypts \fBblocksize()\fR bytes of \f(CW$data\fR and returns the corresponding
ciphertext.
.IP decrypt($data) 4
.IX Item "decrypt($data)"
Decrypts \fBblocksize()\fR bytes of \f(CW$data\fR and returns the corresponding
plaintext.
.SH "SEE ALSO"
.IX Header "SEE ALSO"
Crypt::CBC, Crypt::Blowfish, Crypt::TEA
.SH ACKNOWLEDGEMENTS
.IX Header "ACKNOWLEDGEMENTS"
.IP "Nishant Kakani" 4
.IX Item "Nishant Kakani"
For writing Crypt::Twofish 1.0 (this version is a complete rewrite).
.IP "Tony Cook" 4
.IX Item "Tony Cook"
For making the module work under Activeperl, testing on several
platforms, and suggesting that I probe for features via \f(CW%Config\fR.
.SH AUTHOR
.IX Header "AUTHOR"
Abhijit Menon-Sen <ams@toroid.org>
.PP
Copyright 2001 Abhijit Menon-Sen.
.PP
This module is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.