Director: Simon S. Lam (more publications)

Key tree approach aka logical key hierarchy

The key tree idea was invented by us and independently by a group in NSA (Wallner, Harder, and Agee). They wrote an Internet draft entitled, "Key Management for Multicast: Issues and Architectures," in July 1997. In the same month, we wrote a UTCS technical report, "Secure Group Communications Using Key Graphs," TR-97-23, July 28, 1997.  The key tree approach is also referred to as logical key hierarchy in Internet RFCs.

The NSA draft was later revised and published as,

D. Wallner, E. Harder, and Ryan C. Agee,
Key Management for Multicast: Issues and Architectures,
RFC 2627, June 1999.

A revised version of our technical report was later published as,

Chung Kei Wong, Mohamed Gouda, and Simon S. Lam,
Secure Group Communications Using Key Graphs,
Proceedings ACM SIGCOMM '98, Vancouver, B.C., September 2-4, 1998.