Some Implementation issues in the Fiat-Naor Broadcast Encryption Schemes

We consider the problems of assignment of keys and construction of common key at the Broadcast center, in the zero-message and one-level broadcast encryption schemes of Fiat-Naor [1]. We propose efficient implementations of key assignment and common key construction, and estimate their complexity. We also propose, in the context of one-level schemes, a quick method for limiting the sizes of perfect hash families constructed as by Fredman, Komi ´os and Szemer ´edi [2].