Vehicle ad hoc network (VANET) provides communication between vehicles and vehicle-to-infrastructure communication. High mobility, high speed of vehicles, fast topology changes, and sheer scale are some characteristics that establish VANET as an intensive research topic different from other types of mobile ad hoc network. In this paper, we improve an existing batch verification system on ID-based group signature and also compare the performance achieved. Then, we analyze the best possible value of the number of signatures to batch at a time for large-scale VANET. In addition, we introduce a scheduling algorithm for signature verification where batch verification cannot be implemented efficiently. Copyright © 2014 John Wiley & Sons, Ltd.