Generating a serial number for product activation

First and foremost, this is not a question about generating a serial number for other products. I am not looking to "hack" other products. Here are my requirements: - I would like to generate a standard looking serial number: AILU7-ABCDE-54321-1234-AFCK-17UDF - I need some process that validates whether or not that serial number is "valid" - This portion does not have to be extremely complex. ie, if all the numbers sum up to a value greater than X - I'd be okay with that, but if there are solutions out there that handle this complexity for me, I'd be happy to use them. - The process that validates the serial number can not be server side. ie, I can not make a request out to an external web server to verify that the serial number is valid. - I need some way to pull out metadata from the serial number. ie, after I have validated that the serial number is correct, i need to be able to read out some values from it: "user limit", "expiration date", etc ... - The verification of the serial number will be done via a ASP.NET MVC 3 application. The generation of the serial number does not have to be done that way though. I'm not looking for a silver bullet that will accomplish all these requirements, but more or less some links to documentation or existing libraries that will help me get started. The only library that I have seen is the XHEO DeployLX library; which is just entirely too much for my needs. Could you please provide me with any information that could point me in the right direction?