Crypting and Decrypting Text

[kumschick]

Hi,

I want to crypt some normal text (Hello World) and then later decrpt it back to the original.

Example:
Hello World -> AISND8F7SD8FSDM9VTU945KT4CW0RE...
AISND8F7SD8FSDM9VTU945KT4CW0RE... -> Hello World

I know that with crypt(); or md5(); I can't decrypt it back.
Does someone has an idear how to do it

Thx

[LordShryku]

[man]mcrypt[/man]