Encode/decode

[Anon]

I need to encode and decode a string(two way encoding) so MD5 and Crypt is not usefull for me, since i need the string back in it's original format.

I have been looking at base64_encode/base64_decode, but if you have a base64_encoded string it's very easy to decode using base64_decode. Is it possible to encode with a secret key?

Or do you know other usefull solutions?

Thanks,
Michael

[Anon]

See the mcrypt section of the PHP manual.

[Anon]

Thanks,
but is it possible to encode/decode with some of PHP built in functions?

I don't like extra Modules or extra software.

[Anon]

Nope; mcrypt is PHP's answer for encryption.