Subset-difference broadcast encryption with blacklisting

Abstract

An encryption scheme is provided in which subset-difference lists are generated by blacklisting subsets corresponding to compromised devices and splitting subset difference lists corresponding to the blacklisted subsets into multiple subset difference lists. In some embodiments, a subset-difference tree is generated. The subset-difference tree includes a plurality of subsets. The subset-difference tree covers a plurality of nodes. Each of the plurality of subsets has an apex node among the plurality of nodes. At least one blacklisted node of the plurality of nodes is determined. A first subset among the plurality of subsets is identified that covers the at least one blacklisted node. A plurality of substitute subsets is determined. Each of the plurality of substitute subsets overlaps the first subset and does not cover the at least one blacklisted node. The plurality of substitute subsets are substituted for the first subset.