Date Added: Jun 2012
Broadcast Encryption (BE) is an important technique for Digital Rights Management (DRM). Two key parameters of a BE scheme are the average size of the transmission overhead and the size of the secret information to be stored by the users. The most important BE scheme till date is the Subset Difference (SD) scheme proposed by Naor, Naor and Lotspiech in 2001 which achieves a good balance of these two parameters. A year later, Halevy and Shamir proposed a variant of the SD scheme called the Layered SD (LSD) scheme which allowed to reduce the size of user storage at the cost of increasing the transmission overhead.