encryption decryption without mcrypt?

Quoting Dave Jones (dave@anti.spam): > Nobody out there has any suggestion of how to encrypt and decrypt a > string without mcrypt? > > I can't use md5() because I'm not comparing two things, I'm trying to > pass a new string from page to page without it being readable. It > doesn't have to be extremely secure, it's not financial data, but it > shouldn't be easy to decrypt by the casual user. > > And I don't have control over my configuration (which does not have > mcrypt installed) so it has to be something I can create in php3. > > How about a simple algorithm for either a single key or public/private > key method? > I had to do something similiar once. I ended up taking the data i wanted to pass and rotating it up or down a specific number of places per letter. then i added a colon and grab a 24 character section of the md5() hash based on the value of the first letter. It's mostly security through obscurity, but without access to the code it would be more work to figure out than the protected resource was worth. -- aaron