If that is not an option, you could certainly store your data using Storable. Save a hash of the records in a Storable file. That way no one can read your records as plain text.
Well, since hashing is usually a one-way operation, neither can you. :) Encryption is probably what you want in this case.
I'd also like to offer my advice to the original poster, and that is to go with a standard encryption algorithm and not roll you own (see the comments for CipherText and CipherTextI for amusing reading on why encryption is hard to do by yourself). There are several good modules on CPAN: Crypt::Blowfish or Crypt::Twofish for example.
/me recommends Applied Cryptography by Bruce Schneier
Cheers,
--Moodster
