k-time encryption for k-time licensing
G. Perkins, Prasanta Bhattacharya · 2003
We introduce the notion of a k-time license for digital content and a method for ensuring its security via a k-time encryption scheme. A k-times license is an agreement that legally allows the purchaser to use the licensed material at most k times. The digital content is only accessible through a provided application that decrypts and re-encrypts the content according to our k-time encryption scheme. The application must use secret keys during this process, a vulnerability since the application resides on the user's PC or electronic device. To help heighten the level of security of our system, we also introduce the idea of hiding secret keys in the heuristic solutions of NP-hard problems and then further extend the security with some other well known methods.