AN IDENTITY-BASED CRYPTOSYSTEM FOR SECURING VEHICULAR AD-HOC NETWORK

Abstract

Vehicular Ad-hoc Networks (VANETs) are wireless-equipped vehicles that form networks spontaneously while travelling along the road to improve traffic safety and efficiency. However, security has been a major challenge for this kind of network. Previous works on the use of identity-based cryptosystems for VANET provided message authentication and integrity but lack membership authentication security feature and efficient end-to-end communication time. Hence, this research addressed these problems by improving the Identity-Based Cryptosystem (IBC) for the security of VANET. The cryptosystem was developed using a non-singular elliptic curve. The public keys of users - vehicles and roadside units were derived from the vehicle’s number plate and location identification number respectively. Pseudo-identities were used to mask the real identity of users to preserve their privacy; timestamp technique was used to determine the freshness of transmitted and received messages while membership authentication mechanism was factored into the cryptosystem to ensure that only valid and authenticated members of the network are allowed to join or communicate on the network. The system developed was simulated in MATLAB 9.4 environment and evaluated using the message delivery ratio, end-to-end delay, and intrusion detection ratio as performance metrics. The message delivery ratio (MDR) was obtained for 200 vehicles moving at various 30 km/h (8m/s), 70 km/h (19m/s), 100 km/h (28m/s), and 120 km/h (30m/s) on different road and traffic types. The overall average percentage message delivery ratio shows that the developed system has 92.54% message delivery compared to the Wan-Zhang Identity-Based Cryptosystem (WZIBC) which has 58.40% message delivery. This is a 34.14% performance improvement. The end-to-end delay was also measured for 50, 100, 150 and 200 vehicles. The result shows that the developed system has a total average of 100.91ms end-to-end delay which is equivalent to 0.51ms per vehicle. When compared with the WZIBC system, it shows that the developed system has a 15.1% performance improvement. The result of the Intrusion Detection Ratio (IDR) shows that the developed system has a total average of 98.5% intrusion detection rate compared to the WZIBC system which has a 93.2% intrusion detection rate. This is a 5.4% performance improvement. In conclusion, the research shows that the improved IBC is capable of securing VANET with much lower end-to-end delay, and high message delivery and intrusion detection ratio. In conclusion, the research established a membership authentication model for secure communication in VANETs, and therefore, can be used for securing vehicular ad-hoc networks and other mobile communication systems.