1Blowfish(3)           User Contributed Perl Documentation          Blowfish(3)
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NAME

6       Crypt::Blowfish - Perl Blowfish encryption module
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SYNOPSIS

9         use Crypt::Blowfish;
10         my $cipher = new Crypt::Blowfish $key;
11         my $ciphertext = $cipher->encrypt($plaintext);
12         my $plaintext  = $cipher->decrypt($ciphertext);
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DESCRIPTION

15       Blowfish is capable of strong encryption and can use key sizes up to 56
16       bytes (a 448 bit key).  You're encouraged to take advantage of the full
17       key size to ensure the strongest encryption possible from this module.
18
19       Crypt::Blowfish has the following methods:
20
21        blocksize()
22        keysize()
23        encrypt()
24        decrypt()
25

FUNCTIONS

27       blocksize
28           Returns the size (in bytes) of the block cipher.
29
30           Crypt::Blowfish doesn't return a key size due to its ability to use
31           variable-length keys. (well, more accurately, it won't as of 2.09
32           .. for now, it does.  expect that to change)
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34       new
35                   my $cipher = new Crypt::Blowfish $key;
36
37           This creates a new Crypt::Blowfish BlockCipher object, using $key,
38           where $key is a key of "keysize()" bytes (minimum of eight bytes).
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40       encrypt
41                   my $cipher = new Crypt::Blowfish $key;
42                   my $ciphertext = $cipher->encrypt($plaintext);
43
44           This function encrypts $plaintext and returns the $ciphertext where
45           $plaintext and $ciphertext must be of "blocksize()" bytes.  (hint:
46           Blowfish is an 8 byte block cipher)
47
48       decrypt
49                   my $cipher = new Crypt::Blowfish $key;
50                   my $plaintext = $cipher->decrypt($ciphertext);
51
52           This function decrypts $ciphertext and returns the $plaintext where
53           $plaintext and $ciphertext must be of "blocksize()" bytes.  (hint:
54           see previous hint)
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EXAMPLE

57               my $key = pack("H16", "0123456789ABCDEF");  # min. 8 bytes
58               my $cipher = new Crypt::Blowfish $key;
59               my $ciphertext = $cipher->encrypt("plaintex");  # SEE NOTES
60               print unpack("H16", $ciphertext), "\n";
61

PLATFORMS

63               Please see the README document for platforms and performance
64               tests.
65

NOTES

67       The module is capable of being used with Crypt::CBC.  You're encouraged
68       to read the perldoc for Crypt::CBC if you intend to use this module for
69       Cipher Block Chaining modes.  In fact, if you have any intentions of
70       encrypting more than eight bytes of data with this, or any other block
71       cipher, you're going to need some type of block chaining help.
72       Crypt::CBC tends to be very good at this.  If you're not going to
73       encrypt more than eight bytes, your data must be exactly eight bytes
74       long.  If need be, do your own padding. "\0" as a null byte is per‐
75       fectly valid to use for this.  Additionally, the current maintainer for
76       Crypt::Blowfish may or may not release Crypt::CBC_R which replaces the
77       default 'RandomIV' initialization vector in Crypt::CBC with a random
78       initialization vector.  (to the limits of /dev/urandom and associates)
79       In either case, please email amused@pobox.com for Crypt::CBC_R.
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SEE ALSO

82       Crypt::CBC, Crypt::DES, Crypt::IDEA
83
84       Bruce Schneier, Applied Cryptography, 1995, Second Edition, published
85       by John Wiley & Sons, Inc.
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88       The implementation of the Blowfish algorithm was developed by, and is
89       copyright of, A.M. Kuchling.
90
91       Other parts of the perl extension and module are copyright of Systemics
92       Ltd ( http://www.systemics.com/ ).
93
94       Code revisions, updates, and standalone release are copyright 1999-2001
95       W3Works, LLC.
96

AUTHOR

98       Original algorithm, Bruce Shneier.  Original implementation, A.M.
99       Kuchling.  Original Perl implementation, Systemics Ltd.  Current main‐
100       tenance by W3Works, LLC.
101
102       Current revision and maintainer:  Dave Paris <amused@pobox.com>
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106perl v5.8.8                       2005-12-02                       Blowfish(3)
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