Re: which crypt:: ?

What are you trying to do? Encrypt a cookie? If that's the case, then you can use any of the Crypt modules, but you want to use Mime::Base64 on it, so it can pass thru the web. Here is an example for Crypt::RC4. The nice thing about RC4 is that it has a pure perl module which you can upload to your server, if they don't have it installed. It's fast, although not the best security(but who are you trying to hide from anyways? It's probably not secure from the government)

#!/usr/bin/perl
use strict;
use warnings;
use Crypt::RC4;
use MIME::Base64;
my $key       = "abcdefghijklm";
my $plaintext = "Hello, World!";
my $encrypted = RC4($key, $plaintext);

my $encoded = encode_base64($encrypted);
my $decoded = decode_base64($encoded);
print "$encoded\n";
print "$decoded\n";

my $decrypted = RC4($key, $decoded);
print "$decrypted\n";
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Re: Re: which crypt:: ? by no_slogan (Deacon) on Feb 01, 2003 at 17:51 UTC
With a stream cipher like RC4, it's extremely important that you NEVER ENCRYPT TWO MESSAGES WITH THE SAME KEY. If you do, the security reduces to that of simple xor encryption -- in other words, no security at all. This problem is mentioned in the Crypt::RC4 docs. Using a string hardcoded into your script as the key is the wrong way to use this module. If you want an out-of-the-box encryption solution, I would recommend Crypt::CBC. There are pure-perl encryption modules you can use with it, if compiling modules is a problem for you.	[reply]

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Re: Re: which crypt:: ?
by no_slogan (Deacon) on Feb 01, 2003 at 17:51 UTC

With a stream cipher like RC4, it's extremely important that you NEVER ENCRYPT TWO MESSAGES WITH THE SAME KEY. If you do, the security reduces to that of simple xor encryption -- in other words, no security at all. This problem is mentioned in the Crypt::RC4 docs. Using a string hardcoded into your script as the key is the wrong way to use this module.

If you want an out-of-the-box encryption solution, I would recommend Crypt::CBC. There are pure-perl encryption modules you can use with it, if compiling modules is a problem for you.

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