in reply to Encryption in Perl?
If you don't mind to install a lot of perl modules, you could use Crypt::OpenPGP. I've been using it for a while, and it works quite well. You can find PGP software for pretty much any platform, so you could code/decode the files anywhere, even without Perl installed.
If installing the dependencies is too much work for you, most crypto modules for popular ciphers are safe and pretty 'standard' - try Crypt::Blowfish or Crypt::Rijndael, for instance. The former has shown it's use and security, the latter has been chosen as standard cypher for encryption of official data by e.g. the American government.
In Section Seekers of Perl Wisdom