README
1DESCRIPTION
2 Maybe you have a web application and you need to store some session data
3 at the client side (in a cookie or hidden form fields) but you don't
4 want the user to be able to mess with the data. Maybe you want to save
5 secret information to a text file. Maybe you have better ideas of what
6 to do with encrypted stuff!
7
8 This little module will convert all your data into nice base64 text that
9 you can save in a text file, send in an email, store in a cookie or web
10 page, or bounce around the Net. The data you encrypt can be as simple or
11 as complicated as you like.
12
13CHANGES
14 Version 0.05 had a few missing subroutine bodies, so quite a few things
15 didn't work! I'm now practising what I preach, and have written some tests!
16
17INTERNALS
18 "Crypt::Simple" is really just a wrapper round a few other useful Perl
19 modules: you may want to read the documentation for these modules too.
20
21 We use "FreezeThaw" to squish all your data into a concise textual
22 representation. We use "Compress::Zlib" to compress this string, and
23 then use "Crypt::Blowfish" in a home-brew CBC mode to perform the
24 encryption. Somewhere in this process we also add a MD5 digest (using
25 "Digest::MD5"). Then we throw the whole thing through "MIME::Base64" to
26 produce a nice bit of text for you to play with.
27
28 Decryption, obviously, is the reverse of this process.
29
30WARNING
31 Governments throughout the world do not like encryption because it makes
32 it difficult for them to look at all your stuff. Each country has a
33 different policy designed to stop you using encryption: some governments
34 are honest enough to make it illegal; some think it is a dangerous
35 weapon; some insist that you are free to encrypt, but only evil people
36 would want to; some make confusing and contradictory laws because they
37 try to do all of the above.
38
39 Although this modules itself does not include any encryption code, it
40 does use another module that contains encryption code, and this
41 documentation mentions encryption. Downloading, using, or reading this
42 modules could be illegal where you live.
43
44AUTHOR
45 Marty Pauley <marty@kasei.com>
46
47COPYRIGHT
48 Copyright (C) 2001 Kasei Limited
49
50 This program is free software; you can redistribute it and/or modify it under
51 the terms of the GNU General Public License; either version 2 of the License,
52 or (at your option) any later version.
53
54 This program is distributed in the hope that it will be useful, but WITHOUT
55 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
56 FOR A PARTICULAR PURPOSE.
57
58