Key exchange protocols for multiparty communication services

Network technology is improving distributed applications. The parties in distributed applications need to exchange secret information to perform a specific task, and these parties form a specific group. Secret message exchanges in the group are likely to be in a secret conference over a network. To perform secret message exchange, one needs a common secret key to encrypt or decrypt messages. The basic idea behind our method is to pass a secret line through a published point. Any attacker who uses only one point cannot recover the secret line. Only the party who knows two points of the secret line can recover the line. Based on this idea, we propose new key exchange protocols and a message exchange protocol. The secret key established through the proposed method is a set of the secret points. Moreover, because the secret key is a set of secret points, it can support the dynamic part of a dynamic peer group that allows new parties to join and parties to leave the group.