Licensing Websites - How does it work?

Question

I've been looking at several sites that offer a form of "linkware" license where you get the website for free but need to keep all links to the developers site in place. Purchasing a license key and adding it to the site (either in a database or some form of config file) removes these links.

I was wondering if anyone has had any experience of running a system like this, specifically how do you generate and check the license keys? I'm thinking of applying a similar model to something I'm working on so any examples in "Classic" ASP would be most appreciated.

Thanks in advance

Answer 1

Generally licences work using a public-key system. Your licence string is simply some info (perhaps with info on which domain name this licence is valid for, for example), signed by your private key. The web app contains the public key, which is used to check the validity of the signature.

I'm sure there are other ways, but this seems to be one of the more robust ones that I know of. :-)

I haven't coded anything in ASP, so I have no examples for you, sorry.