Date Added: Jul 2012
In this paper, the authors propose a novel secure multicast architecture that reduces the impact of the 1 affects n problem significantly by exploiting a cryptographic primitive, "Proxy re-encryption". Therefore, they call the proposed secure multicast architecture Sempre (SEcure Multicast architecture using Proxy Re-Encryption). Proxy re-encryption allows intermediate routers to convert the cipher-text encrypted with one key to cipher-text encrypted with another key, without revealing the private key or the plaintext. If the intermediate routers are given proper keys, they can provide separation between subgroups and thereby achieve the goals of scalability and containment. Successful containment reduces the 1 affects n problem significantly. They also compare several related schemes, and discuss some security problems that they identified in them.