|Problems? Is your data what you think it is?
Welcome to the world of encryption, we can share our secrets wtih you but then we will have to kill you ;-)
Seriously, if you are wanting to learn more about encryption I would highly recommend picking up Applied Cryptography: Protocols, Algorithms, and Source Code in C by Bruce Schneier at some point...
Yes, I know...it's not a perl book but it is an excellent resource on cryptography programming as evidenced by the well used copy I keep borrowing from DrManhattan
For your specific application, are you wanting to use symmetric encryption...say, to store a file away from prying eyes. Or, do you need something asymmetric like PGP to send an encrypted file...i.e. an e-mail to someone so they can decrypt it?
If you are wanting symmetric encryption of a file, then Crypt::CBC is a breeze...
To Encrypt using Blowfish...
And to decrypt...
That should get you started