An Efficient and Secure Protocol for Multi-party Key Establishment
Gwoboa Horng · The Computer Journal · 2001
In this paper, a multi-party key establishment protocol based on the difficulty of calculating discrete logarithms in a finite field is proposed with the following features. It requires a constant number (independent of the number of participants) of rounds. All messages have the same constant size. All participants perform a constant number of exponential operations. All participants agree on a key together with two random integers simultaneously. Furthermore, to establish a new key when the set of participants is changed is easy. We also show that this new scheme is secure against passive attacks provided that the Diffie–Hellman key agreement protocol is secure in the sense that the established key is computationally indistinguishable from a random value.