Triplet Authentication System for Efficient Quality of Service in Vehicular Ad hoc Network

Vehicular Ad hoc Network (VANET) is a type of network derived from Mobile Ad hoc Network (MANET). Authentication plays a major role in VANET for the providence of secured communication among vehicles [1]–[3]. Authentication in this network is achieved by cryptography techniques, signature algorithms and message verifications. In VANET, the vehicles share some sensitive information related to safety and hence the need for authentication is high. Authentication schemes in VANET are studied in several research papers in recent years. In [4], authentication was provided for performing secure data transmission based on the identity. Identity was the major parameter considered with which the data was encrypted and forwarded to other vehicle. Hereby the data was decrypted and retrieved first and then Identity was verified. A lightweight authentication was proposed for performing three different mutual authentications [5]. The vehicles those are moving at similar velocity were defined into a cluster in which a head node was chosen based on trust values. Clustering based on this metric involves more number of vehicles into a cluster or only few vehicles in a cluster. Both the processes of clustering and head selection need to be repeated. Similar procedure is followed for all the three authentication which is concluded with a password update phase. Authentication was also provided by using certificates which is uniquely generated for each vehicle. An efficient privacy preserving authentication and key distribution technique was proposed for distributing group keys [6]. The vehicle registers into trusted authority with identity and other credentials, these are required during authentication. Trusted authority generates fake identity for each vehicle to provide security. This entire authentication failed to minimize the working of trusted authority. Identity Based Online / Offline Signature scheme was proposed in [7]. This scheme follows setup, extraction, signature generation (Online using online key, Offline using offline key) and verification. The keys involved in signature generation are varied periodically which leads to complexity and the use of RSA algorithm consume higher time. An anonymous authentication protocol was presented based on cooperative authentication method [8]. Using this protocol group keys are periodically generated and distributed by trusted authority. The keys are managed by the construction of a tree that consumed higher storage due to the increase in keys. Another scheme called conditional privacy-preserving and authentication was proposed to optimize signature generation and verification [9]. This scheme used pseudonym based signature for identity authentication. More than one hash value and pseudonym identity is involved which makes this scheme complex. Dynamic Pseudonym was proposed based on traffic aware VANET environment [10]. Traffic-Aware Pseudonym Changing Strategy was presented in which traffic density is noted and pseudonyms are changed. But the traffic density in VANET is not the right choice for changing pseudonym. Dual authentication and key distribution technique was presented to enhance quality of Service [11]. Two special parameters are computed by trusted authority for generating signature. Authentication is performed only by the trusted authority using this technique. One-time identity based aggregate signature technique was proposed in which multiple trusted authorities are involved in the environment [12]. However several authentication schemes were proposed, they exist with some limitation which needs to be resolved. Previous works aimed to provide security either for Vehicle to Vehicle Communication or Vehicle to Infrastructure Communication. To overwhelm the authentication problems existed in VANET, we have proposed a novel VANET architecture. Many previous research works have focused authentication only for single type of communication. Our aim is to concentrate authentication in entire VANET wherever the communication is held. The proposed VANET is comprised of Vehicles, Roadside Units (RSU), Trusted Authority (TA) and Authentication Server (AS). Authentication is provided between the following entities (1) Vehicle to Vehicle authentication, (2) Head Vehicle to RSU authentication and (3) RSU authentication. Each authentication is performed by an entity which is in higher position than itself. For faster authentication the vehicles are grouped by using Four-Quadrant Partitioning. The road lane is equally divided into segments of equal area, for instance say 100m. In each segment mid-point is predicted and the segment is partitioned into four parts, in which the vehicles in two parts move in same direction and the other two parts in opposite direction. Head vehicle in each part is chosen based on these metrics trust value, node degree and mobility speed using Firefly algorithm. Each vehicle and RSU is registered to TA and the information is shared with AS for the purpose of authentication. Vehicle registers with a unique fingerprint and Identity, whereas RSU registers with unique identity and password. The RSU’s password is static and it cannot be changed. The process of each authentication is illustrated below: (1) Vehicle to Vehicle Authentication: Vehicle to Vehicle communication is involved in VANET for sharing information between vehicles. This authentication is performed using Time based Diffie Hellman algorithm in which time is included for faster authentication. The parameters taken in account for this authentication are fingerprint and token. The fingerprint is converted into binary and while authentication XOR operation is performed for verification. Token is a unique entity that consists of vehicle ID and its signature. Signature is generated using ECDSA and all the parameters are verified by other vehicle. (2) Head Vehicle Authentication: Each head vehicle is authenticated by RSU present in its communication range. RSU authenticates the head vehicle by verifying location, a unique point which is provided by TA during the election of head and Quadrant ID. These values are encrypted using Homomorphic encryption along with a timestamp and forwarded to RSU for verification. After authentication the head vehicle access data, if failed it is reported to TA. (3) RSU Authentication: RSU is authenticated by TA periodically to ensure that RSU is legitimate in the network. RSU ID and Password is verified for authenticating an RSU, here encryption is not used since the channel between them is secure. Our proposed VANET is executed and their result achieves better performances in terms of the following Quality of Service metrics as: 1. Throughput 2. Delay with respect to number of vehicles / time 3. Packet Delivery ratio with respect to number of vehicles / time Proposed VANET Architecture