A Survey of Security Services, Attacks, and Applications for Vehicular Ad Hoc Networks (VANETs) <s> Identity-Based Cryptography Schemes <s> Vehicular ad hoc network (VANET) can offer various services and benefits to users and thus deserves deployment effort. Attacking and misusing such network could cause destructive consequences. It is therefore necessary to integrate security requirements into the design of VANETs and defend VANET systems against misbehavior, in order to ensure correct and smooth operations of the network. In this paper, we propose a security system for VANETs to achieve privacy desired by vehicles and traceability required by law enforcement authorities, in addition to satisfying fundamental security requirements including authentication, nonrepudiation, message integrity, and confidentiality. Moreover, we propose a privacy-preserving defense technique for network authorities to handle misbehavior in VANET access, considering the challenge that privacy provides avenue for misbehavior. The proposed system employs an identity-based cryptosystem where certificates are not needed for authentication. We show the fulfillment and feasibility of our system with respect to the security goals and efficiency. <s> BIB001 </s> A Survey of Security Services, Attacks, and Applications for Vehicular Ad Hoc Networks (VANETs) <s> Identity-Based Cryptography Schemes <s> The basic requirements for secure communication in a vehicular ad hoc network (VANET) are anonymous authentication with source non-repudiation and integrity. The existing security protocols in VANETs do not differentiate between the anonymity requirements of different vehicles and the level of anonymity provided by these protocols is the same for all the vehicles in a network. To provide high level of anonymity, the resource requirements of security protocol would also be high. Hence, in a resource constrained VANET, it is necessary to differentiate between the anonymity requirements of different vehicles and to provide the level of anonymity to a vehicle as per its requirement. In this paper, we have proposed a novel protocol for authentication which can provide multiple levels of anonymity in VANETs. The protocol makes use of identity based signature mechanism and pseudonyms to implement anonymous authentication with source non-repudiation and integrity. By controlling the number of pseudonyms issued to a vehicle and the lifetime of each pseudonym for a vehicle, the protocol is able to control the level of anonymity provided to a vehicle. In addition, the protocol includes a novel pseudonym issuance policy using which the protocol can ensure the uniqueness of a newly generated pseudonym by checking only a very small subset of the set of pseudonyms previously issued to all the vehicles. The protocol cryptographically binds an expiry date to each pseudonym, and in this way, enforces an implicit revocation for the pseudonyms. Analytical and simulation results confirm the effectiveness of the proposed protocol. <s> BIB002 </s> A Survey of Security Services, Attacks, and Applications for Vehicular Ad Hoc Networks (VANETs) <s> Identity-Based Cryptography Schemes <s> In Vehicular Ad hoc NETworks (VANETs), authentication is a crucial security service for both inter-vehicle and vehicle-roadside communications. On the other hand, vehicles have to be protected from the misuse of their private data and the attacks on their privacy, as well as to be capable of being investigated for accidents or liabilities from non-repudiation. In this paper, we investigate the authentication issues with privacy preservation and non-repudiation in VANETs. We propose a novel framework with preservation and repudiation (ACPN) for VANETs. In ACPN, we introduce the public-key cryptography (PKC) to the pseudonym generation, which ensures legitimate third parties to achieve the non-repudiation of vehicles by obtaining vehicles’ real IDs. The self-generated PKC-based pseudonyms are also used as identifiers instead of vehicle IDs for the privacy-preserving authentication, while the update of the pseudonyms depends on vehicular demands. The existing ID-based signature (IBS) scheme and the ID-based online/offline signature (IBOOS) scheme are used, for the authentication between the road side units (RSUs) and vehicles, and the authentication among vehicles, respectively. Authentication, privacy preservation, non-repudiation and other objectives of ACPN have been analyzed for VANETs. Typical performance evaluation has been conducted using efficient IBS and IBOOS schemes. We show that the proposed ACPN is feasible and adequate to be used efficiently in the VANET environment. <s> BIB003
The identity-based cryptography (IBC) is similar to the asymmetric cryptography, in which the user public key can be obtained from their ID information such as user location, telephone number, email address, and more. In order to authenticate the message, the IBC authentication schemes did not utilize PKI certificates. Thus, it significantly reduced the communication overhead and managed overhead of CRLs. In Reference  , Shim proposed an efficient conditional privacy-preserving authentication (CPAS) scheme. This scheme utilized pseudo-IBS in order to obtain secure communication in V2I. In this scheme, the RSU is able to verify the large amount of received messages simultaneously, which significantly reduced the large amount of computational time and also reduced the memory space. In Reference BIB001 , Sun et al. proposed a VANET security system to obtain the vehicle's privacy by utilizing an identity-based cryptography system. In this scheme, an authentication is accomplished without needing a certificate. Since the proposed scheme did not uses certificates, it consumes less memory space, and the message and computational overheads are reduced, as compared to other methods. In Reference BIB002 , Bhavesh et al. introduced an authentication with multiple levels of the anonymity (AMLA) protocol by utilizing pseudonyms and identity-based signature (IBS) scheme. In this approach, the AMLA protocol significantly reduced the message overhead as compared to other PKI methods. Li et al. BIB003 proposed a public key cryptography technique to generate the pseudonym. In this scheme, the identity-based signature (IBS) and ID-based online/offline signature (IBOOS) schemes are utilized for the authentication between V2V and vehicle to road side unit (V2R). These schemes provide authentication, privacy-preservation, and non-repudiation. However, the handling of managing certificates is complex in IBS and IBOOS authentication schemes.