Concurrently Deniable Group Key Agreement and Its Application to Privacy-Preserving VANETs

Algorithm 1

DB-GKA protocol without authentication.

Round 1: Participant performs the following steps:

(1) Choose and compute .

(2) Broadcast message .

Round 2: Upon receiving messages and , each does as following:

(1) Compute , , .

(2) Broadcast message .

Session Key Generation: Upon receiving all messages , each carries out the following steps:

(1) Compute orderly , .

(2) Check . If it is true, continue; Otherwise, abort.

(3) Generate the session key .