I am writing a client-side DHTML app that I want to limit its use by an expiration key.
Obviously this is more of a deterrent than top-shelf software protection, but it will suffice if I can actually pull it off because its users are low-risk candidates (unlikely hackers).
The code will be obfuscated. It uses Google Gears for its local data services. Its manifest file should download an encrypted string containing a date after which the script will lock-up and promote the user to my server. The server will be running PHP and should, upon a successful purchase respond with a new encrypted date string that the obfuscated client code will then update and start working again.
Any general direction for doing so would be most greatly appreciated. This probably isn't a common request.
So basically, how do I get started?