The basis of vehicular ad hoc networks (VANETs) is the exchange of data between entities, and making a decision on received data/event is usually based on information provided by other entities. Many researchers utilize the concept of trust to assess the trustworthiness of the received data. Nevertheless, the lack of a review to sum up the best available research on specific questions on trust management in vehicular ad hoc networks is sensible. This paper presents a systematic literature review to provide comprehensive and unbiased information about various current trust conceptions, proposals, problems, and solutions in VANETs to increase quality of data in transportation. For the purpose of the writing of this paper, a total of 111 articles related to the trust model in VANETs published between 2005 and 2014 were extracted from the most relevant scientific sources (IEEE Computer Society, ACM Digital Library, Springer Link, Science Direct, and Wiley Online Library). Finally, ten articles were eventually analyzed due to several reasons such as relevancy and comprehensiveness of discussion presented in the articles. Using the systematic method of review, this paper succeeds to reveal the main challenges and requirements for trust in VANETs and future research within this scope.

Quantum computing is emerging as a significant threat to information protected by widely used cryptographic systems. Cryptographic methods, once deemed secure for decades, are now at risk of being compromised, posing a massive threat to the security of sensitive data and communications across enterprises worldwide. As a result, there is an urgent need to migrate to quantum-resistant cryptographic systems. This is no simple task. Migrating to a quantum-safe state is a complex process, and many organisations lack the in-house expertise to navigate this transition without guidance. In this paper, we present a comprehensive framework designed to assist enterprises with this migration. Our framework outlines essential steps involved in the cryptographic migration process, and leverages existing organisational inventories. The framework facilitates the efficient identification of cryptographic assets and can be integrated with other enterprise frameworks smoothly. To underscore its practicality and effectiveness, we have incorporated case studies that utilise graph-theoretic techniques to pinpoint and assess cryptographic dependencies. This is useful in prioritising crypto-systems for replacement.

In intelligent vehicular networks, vehicles have enhanced sensing capabilities and carry computing and communication platforms to enable new versatile systems known as Vehicular Communication (VC) systems. Vehicles communicate with other vehicles and with nearby fixed equipment to support different applications, including those which increase driver awareness of the surroundings. This should result in improved safety and may optimize traffic. However, VC systems are vulnerable to cyber attacks involving message manipulation. Research aimed at tackling this problem has resulted in the proposal of multiple authentication protocols. Several existing survey papers have attempted to classify some of these protocols based on a limited set of characteristics. However, to date there is no generic framework to support the comparison of these protocols and provide guidance for design and evaluation. Most existing classifications either use computation complexity of cryptographic techniques as a criterion, or they fail to make connections between different important aspects of authentication. This paper provides such a framework, proposing a new taxonomy to enable a consistent means of classifying authentication schemes based upon seven main criteria. The main contribution of this study is a framework to enable protocol designers and investigators to adequately compare and select authentication schemes when deciding on particular protocols to implement in an application. Our framework can be applied in design, making choices appropriate for the intended context in both intra-vehicle and inter-vehicle communications. We demonstrate the application of our framework using two different types of case study: individual analysis and hypothetical design. Additionally, this work makes several related contributions. We present the network model, outline the applications, list the communication patterns and the underlying standards, and discuss the necessity of using cryptography and key management in VC systems. We also review the threats, authentication, and privacy requirements in vehicular networks.

Standards such as the American IEEE 1609, European ETSI ITS-G5, and Japanese ARIB STD-T109 aim to establish Cooperative Intelligent Transportation Systems (C-ITS) by enabling Vehicular Ad-Hoc Networks (VANETs). In VANETs, vehicles communicate with other vehicles and roadside infrastructure to support latency-critical applications which increase driver awareness of the surroundings. This should result in improved safety and possibly optimizing traffic. However, to secure VANET communications against message manipulation or replaying, security standards such as IEEE 1609.2 and ETSI TS 103 097 are proposed. In this work, we implement the cryptographic primitives recommended in the IEEE 1609.2 standard to authenticate low latency safety critical messages. We evaluate the effect of the implementation using metrics such as CPU clock cycles per operation, average computation time in milliseconds, and message size in bits. We perform a simulation presenting a high-density highway scenario for the above mentioned C-ITS standards. For each standard, we evaluate the number of safety messages that can be successfully received within 100 ms latency. We show how and to what extent the authentication overhead of latency-critical messages may impact on driver safety. Under an assumed traffic scenario, we show that a crash is possible, as a result of the evaluated authentication delay. We show that the recommended algorithms with specific parameters can be a potential solution for low latency safety-critical applications in a large scale scenario.

Wireless broadcast transmission enables Inter-vehicle or Vehicle-to-Vehicle (V2V) communication among nearby vehicles. This communication supports latency-critical applications for improved safety and maybe optimized traffic. However, V2V communication is vulnerable to cyber attacks involving message manipulation. Mechanisms are required to ensure both authenticity and integrity of broadcast data, while maintaining drivers privacy against surveillance. Considering the limited computational resources of vehicles and the possibility of high traffic density scenarios, authentication processes should have low computational overhead. Prior research has produced multiple authentication protocol proposals based on digital signatures, hash functions, or Message Authentication Codes (MACs). To date, there is no computationally efficient secure broadcast authentication scheme tolerable by the vehicles resource-constrained On-Board Units (OBUs) for latency-critical applications in heavy traffic conditions. This paper provides a new secure, efficient, and privacy-preserving scheme proposing Anonymous Lightweight Inter-vehicle (ALI) broadcast authentication with encryption. ALI provides a high level of anonymity by combining a message authentication scheme with beacon encryption. The cryptographic overhead for V2V communication in the ALI scheme is only 149 bytes, and can handle authentication of approximately 700 broadcast messages every 100 milliseconds. This demonstrates the suitability of the ALI scheme in heavy traffic scenarios. We show the security and efficiency of our proposal by conducting security proof and performance analysis.