Similar questions: Best way to generate activation codes for software and How to generate a simple registration code,based on input given by the user and verifying it after installation
My question/use is similar to that of how Microsoft handled the All-in-One Vista disks. During the Vista install, if it did not detect a specific version to install, it asks for a keycode, then knows which version to install. My application is in Visual Basic 2010, and I would like to use keycodes to have the user unlock certain features based on what code(s) he/she has. So the code needs to be built into the software (or rather, an algorithm) so it knows what to unlock, but not be obvious enough that a black hat hacker knows that bit #xx unlocks feature xxxx. If someone posts code from another .NET or PHP, then I can translate to VB code.
My goals are to not have the codes easily guesses, and still have over 20,000 codes generated that can be converted into a set of features, plus verifying it’s a unique user registering or activating the software
In direct response to your question I would take a look at this project; it may be relevant to what you are trying to do: http://keygen.codeplex.com/
However, since you are not installing an OS and instead installing an application I would recommend using a server based DRM setup. The flow for something like this would be:
This solution ensures that it is impossible to modify/create new keys without access to the server. If you are using something like GUIDs on the server side then it also makes it virtually impossible to guess at a key.