>Hello,
>How can I implement the equivalent to sys(2007) in vb.net?
>I do not mean some checksum function, I need to generate the exact same output given the same input.
>
>Thanks in advance.

But sys(2007) is about checksum and all checksum functions is about one way hashing. That's given the same input you get the same output. It doesn't protect from 2 different inputs giving the same result though not happens in practice.
Check "Cryptography Simplified in Microsoft .NET" on MSDN help.
Cetin