Post-quantum identity-based traitor tracing

In the distribution of digital content, users may collude and utilize their secret keys to create pirate decoders which enable illegally users to receive the same service. As a useful countermeasure, the notion of identity-based traitor tracing (IBTT) scheme was introduced for the data owner to trace down pirates and simplify certificate management process. As far as we know, various IBTT schemes have been proposed in the literature and all of them are designed on classical hardness assumptions, which are believed to become broken in the coming post-quantum era. To address this issue, we propose the first post-quantum IBTT scheme in this work. The new IBTT scheme is proved to be secure in the quantum security model, assuming the quantum-resistant hardness of the underlying learning with errors problem. Notably, compared with other IBTT schemes, our construction has the minimal size increasing to make the underlying encryption scheme traitor tracing.