A Survey: Security Challenges of Vanet And Their Current Solution

: Vehicles have a very crucial role in our routine life; we use different kinds of transportation in our living world, massive increasing vehicle on the road insisting serious problem such as traffic jam, vehicle congestion, road accidents, the demand for more fuel etc., to subdue the all those problems, the technology has used which is called VANET (Vehicular ad-hoc networks) VANET is self-organized wireless network when it has demanded to make communication between vehicles to vehicles and vehicles to infrastructure. VANET successfully implements the intelligent transportation system (ITS), even the vehicles having short-range networks. Due to the rapid change of network topology, the VANET installation is challengeable on the vehicles. To give a safe drive and reduce car accidents, the communication among drivers of vehicles and roadside devices makes sure that should be authenticated; any wrong modification (or) correction in real-time communication may create system failure and affect road safety. This article provides a brief description of various challenging issues in VANET and presents some existing solutions for these problems. Later, we discussed the current status of research and future goals. With this article, researchers and academicians can have a more detailed VANET and research trends in this emerging field.


I Introduction
VANET is one type of MANET; VANET is used in ITS (Intelligent Transportation System) to allow people to travel their road safety journey. In VANET, the vehicles able to communicate with another one as well as roadside units (RSU) which are at the edge of the platform of the road, the moving nodes (vehicles) providing unfixed network topology, so VANET do not have any central place to administrate the nodes, the communication established at the time of need depends on wireless range. The VANET is not controlled under of the owner of the node always, nodes could be stolen, and hackers can be tamper on the communication information; various types of cyberattacks happen in VANET, unpredicted and predicted an authorized node drives attacks, unpredicted attacks demarche by authenticated nodes, predicted attacks [3]. We produce and discuss the various kinds of attacks on a wireless network is a detailed manner. This survey will help the forthcoming researchers to categories of security challenges for their work [9]. In VANET, we classify four domain nodes. First, the domain is a node (Vehicle) with a radio system, Bluetooth or wireless device ( GPS ), I a:-Vehicle --> to --> sensors ( lidar and Radar) and Event Data Recorder (DR). I b. Vehicle --> to--> personal devices. Second domain nodes are roadside unit (RSU) to communicate with the base station and vehicle act as gateways. The third domain is the vehicle called VANET on board unit (OBU) fourth domain is a nearby cellular base station [5] [7]. The vehicles are designed with VANET to inform the traffic congestion and road accident around them to nearby base stations and roadside unit ( RSU). Besides, inter vehicles communicate with them regarding speed, direction, proximity and other parameters without driver intrusion [6].

Research Article Research Article
This paper develops a survey on secure vehicular communication system based on Adhoc network principles and wireless LAN technology for car-to-car communication [9].

II BACKGROUND STUDY
This section provides a research report on the latest potential solutions that offer protection to the VANET network. In this way, we can discover the most important pattern and the current solution for each thread. Several securities have been proposed to date, and various analysis papers have been introduced to fix these VANET protection concerns addressed in this document. Public Key Strategy Based This method retains the security of the post, where the vehicle has a private key sign and its certificates are still attached. The authentication of the message takes place at the receiving end, where the recipient verifies the key used to sign the message and verifies the message during verification. Author [2] addressed this strategy and then used the ECC to minimize the network. Community Signing Based Strategy There are two key problems with this strategy. Firstly, this concept creates a great deal of overhead as a new car joins the group, and secondly, the versatility that keeps a network from keeping a group static. Author in [12] addressed Signcryption and Community Signature in order to fulfil a range of protection concepts. Zhang et al [8] Idea using the group signature is recommended.

III. COMPARATIVE ANALYSIS OF SURVEY
Mobility makes a group dynamic and prevents it from making a static.
Kenneth et al. [10] CRLs distribution by using vehicles in an epidemic manner. Improves distribution speed Bandwidth and Hardware constraints. Performs approaches that only employ RSUs distribution points Jasson et al. [11] Used lightweight method for exchanging CRL updates Reduction in certificate revocation lists size Long CRLs due to huge no. of vehicles Low performance in high traffic region Zhang et al [ 12] Discussed Signcryption and group signature mechanism to achieve security principles. Using this protocol specific feature such as mobility, physical road limitations can be exploit efficiently, and properly distributed RSUs.
If any RSU collapsed, than particular network's working gets disturbed. With increase in load ,performance rate decreases Loot the important and personal information from the driver ( or) owner of the car.

High
Blackhole & Grey hole The information has blocked instead of spread over the network.

Moderate
Man-in the middle It happens when a malicious node breaks the relay (or) manipulating the real messages exchanged between the legitimate nodes.

Timing attacks
The real-time content creation has changed. High

Injection attack
The attackers inject the wrong information into the automotive bus system.

High
Location tracking Attackers can collect and modify the location tracking information for tracking attacks. Flooding attack Plenty of packets are falling on a node to make the node not available condition.

High
Jamming attack The attacker uses the jammer signal to jam the channel.

Medium
Amalgamation attacks A group of illegitimate node gathered to start malicious attacks like isolate the legitimate node.
Low Table 2: possible security challenges, the followings are the most feasible solution for the above attacks.

V PROPOSED TRENDY SOLUTIONS 1. Cryptography style solutions
Cryptography also the best solution for secure communication between users by using protocols that avert an illegitimate person from access. Encryption is one of the cryptography-based techniques where it transforms the data into code by using an advanced algorithm the indented users can only read and prevent outside attackers. In VANET System, each vehicle apply the encryption and digital signature for getting secured message communication with the Vehicle and RSU Key distributed Encryption technique gives a feasible solution for the attacks such as maninthe -middle attack, replay attack.

2.SEAD (Secure and efficient ad-hoc distance vector )
Its works are based on the DSDV routing protocol (Discetinanation sequenced distance vector). Some of the Nodes have low CPU processing capability in which attackers try to exploit more network bandwidth SEAD supports that type of nodes by using one way Hash function and Symmetric cryptography. In Dos Attack, the attackers transmit more traffic information than the CPU capacity to handle, for that one way hash Function is used with that node, which is choosing the Random initial value, then, the List of values are calculated like V0,V1,V2,……Vn, V0=X , Vi=H(Vi-1) for ) 0 < I ≤ n. for authentication Vi can authenticate Vi-4 By developing H(H(H(H(vi-4)))). Using destination sequence number easily escape from repeated routing path, and replay attack can identify in the packet using the destination sequence number.

VatiCAN
The CAN mechanism is deployed for connected electronic vehicle units inside the car.

Integrity
Alter the Real message The compromised node modify and spread the information from what they get.

Forgery attacks
The compromised node changes the actual time and the right location.

Illusion attack
The compromised node deceives the sensors of a car and sends wrong traffic warning messages to the neighbours.

Masquerading
The attackers capture the legitimate identity to obtain confidential information.

High
Broadcast tampering The attackers use the vehicle maintenance period to tamper with the hardware of the vehicle. High