A New Joint Fingerprinting and Decryption Scheme based on a Lattice Problem

We propose a new encryption scheme that supports joint fingerprinting and decryption. The scheme is remarkably resistant to known-plaintext attack and collusion attack (e.g. average attack or other linear combination attack) on keys. Interestingly, the security of our scheme is relied on a lattice problem: Given a collection of random lattice points generated from a short basis of a lattice, find the short basis. The scheme can be used as a traitor-tracing scheme or a buyer-seller watermarking scheme.