I wanted to know if there exists a somewhat simple, but secure, method to encrypt strings(not passwords), with a password which is not stored on the server, in PHP.
I've checked A reversible password encryption routine for PHP, but I'm unsure if it is secure enough if intruders have access to the server and source.
We're talking about a automatic system where a computer sends a request to a server, which stores information in a log. So I'm thinking I could send the encryption password in the request header, preferably encrypted, but then it would be difficult to decrypt without storing the password somehow on the server. Wait, I think i might be complicating things a bit too much, but I hope you get the idea... It's meant to keep the information safe, even if hackers have full control over the server.