A Vehicular Ad hoc Network (VANET) is a type of mobile Peer-To-Peer wireless network that offers communication among nearby vehicles, between vehicles and nearby fixed roadside unit. With technological advancement and rapidly increment of vehicles, recent VANET applications such as safe driving and emergency salvation often require high position accuracy, data integrity and reliability. But present existing systems cannot fulfill the requirements of VANET security. For data authentication, integrity and security in routing system, security analyzers appoint hybrid cryptography using Advanced Encryption Standard (AES) and Elliptic Curve Cryptography (ECC) algorithms. ECC is used as asymmetric cryptography to encrypt the AES private key and routing data is encrypted by AES symmetric cryptography. AES, ECC algorithms provides adequate and efficient security for VANET. The main objectives of our research are to provide better security against various attacks in data link layer, to consume less network resource, to use shorter key size in case of longer messages and to provide faster encryption and decryption time.
Road accident is one of the major causes of death and injuries in the world. For this reason Vehicular Ad Hoc Network (VANET) becomes very important issue in recent research area to improve the safety and comfort travel in case of very high road traffic. In a VANET, each vehicle is assumed to have an On-Board Unit (OBU). Road-Side Units (RSU) that is installed along the roads. Some application servers and A Trusted Authority (TA) are installed in the back end. The OBUs and RSUs communicate using the Dedicated Short Range Communications (DSRC) protocol over the wireless channel. The RSUs, TA, and the application servers communicate by using a secure fixed network.
Secured VANET is very necessary for ensuring safe driving, avoiding collision and accident. A number of security cryptography are designed for this purpose but hybrid cryptography is the best one. Here, we also propose a hybrid cryptography consists of ECC and AES. We are optimistic that our proposed method will provide better security against various attacks in VANET, better information processing time and offer better performance for longer messages. We are intended to simulate this hybrid method for showing that our experimental results are better than other existing systems. So, our future work is to simulate this proposed method by using NS2(Network Simulator-2).
At present there exist several individual cryptography systems based on either symmetric or asymmetric key cryptography. Both cryptography have some drawbacks. Intruders are becoming technically more skilled to break the security of these existing systems in terms of VANET day by day. As a result these cryptography systems are also becoming more vulnerable. On the other hand, when security is concerned then we face some other problems such as consuming more power and resource. To reduce these problems a number of hybrid cryptography systems have proposed recently. Still, there remain some problems in these hybrid cryptography systems. In terms of different situations we have find out some problems in present existing systems for VANET security as follows:
1. Asymmetric key cryptography enhances the security level but it has the problem of consuming high amount of network resources in terms of memory and computations.
2. Symmetric key cryptography requires less network resources but provides less security because same key is used for encryption and decryption. The widely used symmetric key cryptography is AES. But its secret key will be break within nearest future.
3. The main problem of using RSA is that it provides same functionality to ECC but with large amount of memory and power consumption. Other problems are RSA has longer keys than ECC for longer messages and it is slower in the case of key generation.
4. In decryption phase the AES-RSA is slower as compared to the decryption time of AES-ECC.