NAME

Crypt::Misty1 - Crypt::CBC-compliant block cipher

ABSTRACT

Misty1 is a 128-bit key, 64-bit block cipher. Designed by Mitsuru Matsui, the inventor of linear cryptanalysis, Misty1 is the first cipher that is provably secure against linear and differential cryptanalysis.

SYNOPSIS

    use Crypt::Misty1;

    $cipher = new Crypt::Misty1 $key;
    $ciphertext = $cipher->encrypt($plaintext);
    $plaintext  = $cipher->decrypt($ciphertext);

DESCRIPTION

Misty1 is a 64-bit symmetric block cipher with a 128-bit key. It was developed by Mitsuru Matsui, and is described in the paper New Block Encryption Algorithm MISTY and in RFC2994.

In January of 2000, the 3GPP consortium selected a variant of Misty1, dubbed as KASUMI (the Japanese word for ``misty''), as the mandatory cipher in W-CDMA.

This module supports the Crypt::CBC interface, with the following functions.

Functions

blocksize

Returns the size (in bytes) of the block (8, in this case).

keysize

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

encrypt($data)

Encrypts 8 bytes of $data and returns the corresponding ciphertext.

decrypt($data)

Decrypts 8 bytes of $data and returns the corresponding plaintext.

EXAMPLE 1

    #!/usr/local/bin/perl

    use diagnostics;
    use strict;
    use warnings;
    use Crypt::Misty1;

    # key must be 16 bytes long
    my $key = "0123456789abcdef";

    my $cipher = new Crypt::Misty1 $key;

    print "blocksize = ", $cipher->blocksize, " bytes \n";
    print "keysize = ", $cipher->keysize, " bytes \n";

    # block must be 8 bytes long
    my $plaintext1 = "Testing1";

    my $ciphertext = $cipher->encrypt($plaintext1);
    my $plaintext2 = $cipher->decrypt($ciphertext);

    print "Decryption OK\n" if ($plaintext1 eq $plaintext2);

EXAMPLE 2

    #!/usr/local/bin/perl

    use diagnostics;
    use strict;
    use warnings;
    use Crypt::CBC;  # CBC automatically loads Misty1 for us

    # when using Crypt::CBC, key may be of ANY length
    my $key = "0123456789abcdef";

    # IV must be exactly 8 bytes long
    my $IV = pack "H16", 0;

    my $cipher = Crypt::CBC->new({'key' => $key,
                                  'cipher' => 'Misty1',
                                  'iv' => $IV,
                                  'regenerate_key' => 1,
                                  'padding' => 'standard',
                                  'prepend_iv' => 0
                                });

    # when using Crypt::CBC, plaintext may be of ANY length
    my $plaintext1 = "This is a test";

    my $ciphertext = $cipher->encrypt($plaintext1);
    my $plaintext2 = $cipher->decrypt($ciphertext);

    print "Decryption OK\n" if ($plaintext1 eq $plaintext2);

MORE EXAMPLES

See Crypt::CBC for more examples using CBC mode. See also the "examples" and "t" directories for some more examples.

COPYRIGHT AND LICENSE

Copyright 2003 by Julius C. Duque <jcduque (AT) lycos (DOT) com>

This library is free software; you can redistribute it and/or modify it under the same terms as the GNU General Public License.