Parallel Key Exchange

In the paper we study parallel key exchange among multiple parties. the status of parallel key exchange can be depicted by a key graph. in a key graph, a vertex represents a party and an edge represents a relation of two parties who are to share a key. we first propose a security model for a key graph, which extends the bellare-rogaway model for two-party key exchange. next, we clarify the relations among the various se- curity notions of key exchange. finally, we construct an efficient key exchange protocol for a key graph using the randomness re-use technique. our protocol establishes the multiple keys corresponding to all edges of a key graph in a single session. the security of our protocol is proven in the standard model.