Hi. Well in either case, the generated serial would look like the following: AF54E45D32E... etc and I want my serial to be formatted like the following: 32443523454234532... etc But, because my serial would be large, that is why I cant simply use int64 or simular methods. I have seen code before, and used it years ago that does exactly what I want. Yes, there are many products that ask for a MD5 style serial, but, if you look at products from ADOBE, AUTODESK etc etc, they have serial numbers in the following format: 0000-0000-0000-0000-0000 But if I simply created a string and forced it to be numbers, which I have managed to do, when it is encrypted we loose the format and end up with unreadable charicters. It is easy to find how to then encode these into a readable format, but it is always base32 or base16 and I still want to represent my large serial as digits. Thank you, I will keep trying to figure this out. Regards, Stephen