University of Texas at Austin
The authors use multi-linear maps to provide a solution to the long-standing problem of public-key broadcast encryption where all parameters in the system are small. In their constructions, cipher-text overhead, private key size, and public key size are all poly-logarithmic in the total number of users. The systems are fully collusion-resistant against any number of colluders. All their systems are based on an O (log N) way multi-linear map to support a broadcast system for N users. They present three constructions based on different types of multi-linear maps and providing different security guarantees. Their systems naturally give identity-based broadcast systems with short parameters.