Abstract:

A secure protocol for digital copyright protection without thirdparty is presented. This protocol makes digital content and license each package separately, and distribute independently, which gets rid of a thirdparty  in the traditional DRM model, thus it can improve efficiency for both the client and the server. License is registered and checked by an online server, implementing the license dynamically allocated. Considering the integrity and security of the dynamic license, cryptography algorithms are used for data encryption and digital signature respectively. Besides, the used license will have been deleted while the online checking is over. The license database will be updated when the licenses are  exhausted, and it is effective to protect copyright from the cloned attack and the collusion attack.

Key words: digital copyright;dynamic license;without thirdparty;license database;P2P