Conditional Privacy-preserving Authentication Scheme Research Articles

Hybrid cryptography-based scheme with conditional privacy-preserving authentication and memory-based DOS resilience in V2X

To secure Vehicle-to-everything (V2X) communications, many Conditional Privacy-Preserving Authentication schemes (CPPA) use symmetric and asymmetric encryption during the authentication process. However, several existing schemes have some security limitations regarding VANET requirements. In many symmetric cryptography-based schemes, the participants are required to share the same keys which could compromise the security of the network in case the key of one participant is compromised, while many asymmetric cryptography-based schemes take much time during the authentication process, and don't address the denial-of-service attack. In this paper, we propose a certificateless scheme that does not require a certificate and prevents the escrow problem. Plus, it uses the elliptic curve cryptography and avoids bilinear pairing and Map-to-Hash functions. We call our scheme Hybrid Cryptography-Based Scheme with a Conditional Privacy-Preserving Authentication (HCBS-CPPA), as it uses both symmetric and asymmetric cryptography during the authentication process. Our scheme combines the strength of an asymmetric encryption that satisfies non-repudiation, and the strength of a symmetric encryption that allows to perform a lightweight authentication. In addition, we show that our scheme is resilient to memory-based Denial of Service (DOS) attack which occurs when an attacker floods the memory of a receiver with invalid messages. A security proof shows that HCBS-CPPA is secure in the random oracle. Regarding the simulation of our scheme, it turns out that HCBS-CPPA has the best performance when compared with several existing certificateless schemes. Additionally, it requires less execution time during the signing and verification process, as well as less communication overhead when compared to the existing schemes.

BPA: A Novel Blockchain-Based Privacy-Preserving Authentication Scheme for the Internet of Vehicles

The Internet of Vehicles (IoV) connects an isolated individual on the road to share information, which can improve traffic efficiency. However, the promotion of information sharing brings the critical security issues of identity authentication, followed by privacy protection issues in the authentication process in the IoV. In this study, we designed a blockchain-based conditional privacy-preserving authentication scheme for the IoV (BPA). Our scheme implements zero-knowledge proof (ZKP) to verify the identities of vehicles, which moves the authentication process down to the Roadside Units (RSUs) and achieves decentralized authentication at the edge nodes. Moreover, blockchain technology is utilized to synchronize a consistent ledger across all RSUs for recording and disseminating vehicle authentication states, which enhances the overall authentication process efficiency. We provide a theoretical analysis asserting that the BPA ensures enhanced security and effectively protects the privacy of all participating vehicles. Experimental evaluations confirm that our scheme outperforms existing solutions in terms of the computational and communication overhead.

An efficient and certificateless conditional privacy-preserving authentication and key agreement scheme for smart healthcare

Smart healthcare overcomes the limitations of time and space, allowing users to access medical and health services anywhere and anytime, thus improving the quality and efficiency of these services. However, due to its excessive reliance on wireless public networks, smart healthcare faces challenges and issues related to communication security. As a result, authentication and key agreement are critical as the first line of defense for smart healthcare communications. Over the past few years, numerous authentication and key agreement schemes have been proposed by experts and scholars, but most of these schemes are not applicable to practical scenarios due to their lack of security and efficiency. To address these issues, we propose an elliptic curve-based certificateless conditional privacy-preserving authentication and key agreement scheme. This scheme does not require endorsement from a Certificate Authority (CA) and features lightweight and secure properties, making it suitable for resource-limited smart healthcare communication. In addition, the security of the proposed scheme is proven under the random oracle model, and its safety is supplemented using BAN logic. Finally, performance analysis reveals that the proposed scheme not only satisfies security property and can withstand general attacks but also offers certain advantages in communication efficiency.

Cryptanalysis of Two Conditional Privacy Preserving Authentication Schemes for Vehicular Ad Hoc Networks

Conditional Privacy Preserving Authentication (CPPA) schemes are an effective way of securing communications in vehicular ad hoc networks (VANETs), as well as ensuring user privacy and accountability. Cryptanalysis plays a crucial role in pointing out the vulnerabilities in existing schemes to enable the development of more resilient ones. In 2019, Zhang proposed a CPPA scheme for VANET security (PA-CRT), based on identity batch verification (IBV) and Chinese Remainder Theorem (CRT). In this paper, we cryptanalyze Zhang’s scheme and point out its vulnerability to impersonation and repudiation attacks. In 2023, Zhang’s scheme was cryptanalyzed by Tao; however, we point out flaws in Tao’s cryptanalysis due to invalid assumptions; hence, we propose countermeasures to Tao’s attacks. Furthermore, in 2021, Xiong proposed a Certificateless Aggregate Signature (CLAS) scheme which is also cryptanalyzed in this paper. Finally, we analyze the causes and countermeasures by pointing out the vulnerabilities in each scheme that enabled us to launch successful attacks and proposing changes that would fortify these schemes against similar attacks in the future.

L-CPPA: Lattice-based conditional privacy-preserving authentication scheme for fog computing with 5G-enabled vehicular system.

The role that vehicular fog computing based on the Fifth Generation (5G) can play in improving traffic management and motorist safety is growing quickly. The use of wireless technology within a vehicle raises issues of confidentiality and safety. Such concerns are optimal targets for conditional privacy-preserving authentication (CPPA) methods. However, current CPPA-based systems face a challenge when subjected to attacks from quantum computers. Because of the need for security and anti-piracy features in fog computing when using a 5G-enabled vehicle system, the L-CPPA scheme is proposed in this article. Using a fog server, secret keys are generated and transmitted to each registered car via a 5G-Base Station (5G-BS) in the proposed L-CPPA system. In the proposed L-CPPA method, the trusted authority, rather than the vehicle's Onboard Unit (OBU), stores the vehicle's master secret data to each fog server. Finally, the computation cost of the suggested L-CPPA system regards message signing, single verification and batch verification is 694.161 ms, 60.118 ms, and 1348.218 ms, respectively. Meanwhile, the communication cost is 7757 bytes.

Conditional privacy-preserving authentication scheme for V2V communication without pseudonyms

Pseudonym is widely used in conditional privacy-preserving authentication (CPPA) scheme for vehicle-to-vehicle (V2V) communication in vehicular ad hoc networks (VANETs) in order to protect user’s privacy. The main disadvantage of pseudonym-based CPPA schemes is that the pseudonym has to be frequently updated, which puts a heavy burden on VANETs, due to linkage-attack. To solve this problem, we proposed a CPPA scheme for V2V communication without involving pseudonyms. The vehicle does not use any pseudonym in the proposed scheme, therefore it is immune to pseudonym updating and management problems. Moreover, the scheme enables secure V2V communication, which means that only legal vehicles have access to the transmitted messages. Security analysis shows that the scheme supports secure properties of anonymity, unlinkability, non-repudiation, message integrity, traceability, and revocation. Performance analysis and extensive simulations show that the scheme is computationally efficient and has the lowest average message delay among compared schemes.

A Security-Enhanced Certificateless Conditional Privacy-Preserving Authentication Scheme for Vehicular Ad Hoc Networks

By adopting advanced Internet of Things (IoT) technology to sense and collect traffic-related information to improve traffic safety and efficiency, the vehicular ad hoc network (VANET) is becoming a prominent application that changes human driving experiences in the current era. Because frequent data exchange occurs in open environments, VANETs are inherently vulnerable to security and privacy attacks. In history, many certificateless aggregate signature (CLAS) schemes with conditional privacy-preserving (CPP) have been proposed to ensure the authenticity and integrity of the exchanged data and protect users’ privacy. However, we reveal that the state-of-the-art schemes cannot be deployed in practical VANET applications by proposing concrete signature forgery attacks. To this end, we propose a new CLAS-based authentication scheme with CPP for VANETs. The rigorous security proofs based on the standard cryptographic assumption show that the scheme has enhanced security. Moreover, theoretical analysis and experimental evaluation illustrate the practicality of our design.

Efficient Conditional Privacy-Preserving Authentication Scheme for Safety Warning System in Edge-Assisted Internet of Things

With the advent of smart cities, the significance of the Internet of Things (IoT) is gaining greater prominence. At the same time, the safety early warning system in the IoT has a significant impact on real-time monitoring and the response to potential risks. Despite the advancements made in edge-assisted IoT deployments, several challenges and constraints persist. Given the potential threat to life posed by safety-related messages, ensuring the authenticity of messages in the edge-assisted IoT safety warning system is crucial. However, considering the identity privacy of devices participating in the edge-assisted Internet of Things system, directly verifying the identity of the sending device is undesirable. To address this issue, in this work, we design a linkable group signature scheme that allows devices to anonymously send safety-related messages to edge nodes, defending against Sybil attacks while ensuring the traceability of malicious device identities. Then, we present a high-efficiency conditional privacy-preserving authentication (CPPA) scheme based on the designed group signatures for the safety warning system in edge-assisted IoT. This scheme effectively protects device identity privacy while providing a reliable authentication mechanism to ensure the credibility and traceability of alert messages. The proposed scheme contributes to the field of safety warning systems in the context of edge-assisted IoT, providing a robust solution for privacy preservation and authentication.

CPAHP: Conditional Privacy-Preserving Authentication Scheme With Hierarchical Pseudonym for 5G-Enabled IoV

As a representative application scenario of the Internet of Things (IoT), the Internet of Vehicles (IoV) plays an important function in the area of intelligent transportation. However, data traffic exchanged in IoV is usually correlated with plenty of sensitive information, thus leading to privacy leakage. Nevertheless, if all personal data about vehicles are completely protected, it will be hard to trace the real identities of malicious vehicles, which also raises other security issues in IoV. In addition, existing schemes are not fully suitable for 5G-enabled IoV due to their complex structure and high computation requirements. In order to realize more efficient communication and anonymous authentication of vehicles with superior security, we propose a conditional privacy-preserving authentication scheme with hierarchical pseudonyms (CPAHP) in 5G-enabled IoV, which is based on the elliptic curve Diffie-Hellman (ECDH) problem. Through the hierarchical pseudonym mechanism, CPAHP can protect the real identities and movement tracks of vehicles. Whereas, if vehicles have malicious behaviors, their real identities can be recovered through the corresponding pseudonyms. Furthermore, by taking advantage of a batch verification method, receivers can easily cope with a huge influx of messages in a short space of time. Moreover, by introducing blockchain technology, traffic information can be shared smoothly among all vehicles. Through the security analysis and performance evaluation, it is demonstrated that CPAHP can not only meet the security requirements but also provide higher computational efficiency.

Schnorr-based conditional privacy-preserving authentication scheme with multisignature and batch verification in VANET

During both Vehicle-to-Vehicle (V2V) and Vehicle-to-Infrastructure (V2I) communications, authentication process is necessary to protect Vehicular Ad Hoc Network (VANET) from cyberattacks. In this paper, an efficient Conditional Privacy Preserving Authentication (CPPA) scheme is proposed which does not require a certificate and overcomes the escrow problem during the authentication process. The proposed scheme uses Elliptic Curve cryptography and avoids Map-to-Hash function and bilinear pairing. In this regard, we call our scheme Schnorr-CPPA since it allows to implement Schnorr algorithm and aggregate signatures into a short signature during the authentication process in VANET. When a roadside unit receives the same message from multiple vehicles, it can verify and aggregate the signatures into one aggregate signature using a multisignature feature and transmit the aggregate signature to a traffic control center for networking management. In addition, a roadside unit can verify different messages coming from vehicles by using a batch verification feature and aggregate the signatures into one signature, and then can transmit the result to a traffic control center. During both the multisignature and batch verification process, our Schnorr-CPPA is resistant against the rogue attack since the roadside unit should check the possession of proof (POP) as a proof that each signer possesses the private key. Additionally, a security proof is given and shows that our scheme is secure in the random oracle. Plus, our simulation proves that Schnorr-CPPA has better performance when compared with several research works regarding time cost for one and multiple messages during the authentication process.

An Unconditionally Secured Privacy-Preserving Authentication Scheme for Smart Metering Infrastructure in Smart Grid

Industry 4.0 allows faster data accessibility, improved performance, fault identification, and remote control of machines within any smart factory. Due to the massive generation of delay-sensitive data, this system demands a robust security mechanism against security threats. In order to mitigate such potential attacks and provide security-free services, this article proposes an edge-based conditional privacy-preserving authentication scheme based on quantum key distribution protocol for secure authentication and secure communication within smart grid infrastructure. Apart from guaranteeing security against threats such as node impersonation, message tampering, and repudiation, the scheme also defends man-in-the-middle attacks, replay attacks, etc. We validate the proposed protocol through a simulation study. The result indicates that it performs reasonably well and enables unconditional security for the data exchanged between entities of smart grid infrastructure.

An Efficient Blockchain-Based Conditional Privacy-Preserving Authentication Protocol for VANETs

Vehicular Ad-hoc Networks (VANETs) have potential applications in improving the efficiency and safety for intelligent transportation systems. The openness of VANETs, however, also introduces privacy and security implications. Despite a number of conditional privacy-preserving authentication (CPPA) schemes with anonymity and conditional traceability have been designed for VANETs, a majority of these schemes cannot be directly applied to a real-world setting (e.g., due to the need for a certificate manager for issuing keys in PKI-based solutions, or the inherent key escrow problem in ID-based solutions). There have also been attempts to design blockchain-based CPPA schemes, but these schemes may not support key revocation or are inefficient (e.g., due to on-chain operations). This paper proposes an efficient blockchain-based CPPA (EBCPPA) scheme, which is designed to mitigate the above limitations. Our proposal consists of two key building blocks, namely: signature of knowledge and smart contract. To evaluate the feasibility, we present the security and performance analyses of EBCPPA. Specifically, the performance evaluations show that EBCPPA is more efficient than other existing state-of-the-art solutions, in terms of signing (improving at least 49.71%), the verification (improving at least 32.84%) and bandwidth requirement (reducing at least 27.59%).

Security Analysis of Conditional Privacy-Preserving Authentication Schemes for VANETs

In order to solve the security and privacy-preservation issues in VANETs, a number of conditional privacy-preservation schemes based on certificateless signatures (CLS) schemes and certificateless aggregate signatures (CLAS) schemes have been proposed. However, most of them were insecure against several types of attacks. Recently,Wang <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et al</i> . and Xiong <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et al</i> . proposed new conditional privacy-preserving authentication schemes based on CLAS and CLS schemes, respectively, for VANETs.We present malicious-but-passive KGC attacks on Wang <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et al</i> .’ scheme, and forgery attacks and key recovery attacks on Xiong <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">et al</i> .’ scheme, where KGC or anyone can generate valid signatures on any messages for any vehicles without being traced by TA. Our attacks break their unforgeability and traceability. At last, we discuss their causes and countermeasures.

CPPABK: conditional privacy-preserving authentication scheme for VANETs based on the key derivation algorithm

CPPABK: conditional privacy-preserving authentication scheme for VANETs based on the key derivation algorithm

Blockchain-based conditional privacy-preserving authentication scheme in VANETs

Blockchain-based conditional privacy-preserving authentication scheme in VANETs

ELCPAS: A new efficient lightweight certificateless conditional privacy preserving authentication scheme for IoV

This paper proposes a new efficient certificateless conditional privacy preserving authentication (CL-CPPA) scheme named ELCPAS, which is pairing-free, energy-efficient, lightweight which uses elliptic curve cryptography (ECC) for internet of vehicles (IoV). The ELCPAS is based on the certificateless signature scheme that eliminates the key escrow problem, which is the drawback of identity-based encryption. It performs batch message verification with a very efficient method which minimizes the delays in the message verification phase. In our proposed scheme, users (vehicle etc.) do not need to communicate with central units during each message signing. Thus, the computational load and connection problems in the central units are minimized. It is also quite fast as it does not use the bilinear pairing and map-to-point operations. The performance evaluation shows that ELCPAS has efficiency in scope of computation cost, communication cost and energy consumption cost compared to other existing schemes. The security evaluation is performed according to the random oracle model (ROM) and the proposed ELCPAS scheme has been shown to be secure. In addition, it provides security requirements and it is resistant to cyber-attacks. The results of the analyses performed according to the security criteria show that it is secure.

ISC-CPPA:Improverd-Security Certificateless Conditional Privacy-Preserving Authentication Scheme With Revocation

With the development of Internet of Things, communication and computer technology, the significance of realizing vehicular ad hoc networks (VANETs) become more important. Due to wireless communication, VANETs suffer cyber attacks in practice. Many anonymous authentication schemes have been proposed in the literature. Li et al. proposed an efficient authentication scheme called CL-CPPA. However, the proposed scheme failed to realize the claimed un-linkability and anonymity. In this work, we proposed a new certificateless conditional privacy-preserving authentication scheme with an enhanced security guarantee. Specifically, a random number is selected to encrypt the unique tag to ensure anonymity. And our proposed scheme also realizes un-linkability, ensuring that attackers cannot determine whether different messages are sent by the same vehicle. Besides, we present a detailed and efficient revocation mechanism in the proposed scheme. Each RSU has its own private key, when there is a malicious vehicle, RSU will immediately update the private key of current area. Only legitimate vehicles can get the new private key, and malicious vehicle is efficiently revoked from the network. The experiment results show that the proposed scheme solves the above problems with little additional extra calculations.

An efficient conditional privacy-preserving authentication scheme with scalable revocation for VANETs

In Vehicular Ad Hoc Networks (VANETs), secure information sharing between vehicles is critical for improving traffic efficiency and driving safety. However, existing identity-based communication protocols for VANETs face problems of over-reliance on ideal Tamper-Proof Devices (TPDs) and the efficiency of verifying multiple messages in areas of high traffic density. Besides, many existing authentication schemes suffer from the heavy workload of revoking malicious vehicles when they misbehave. For addressing these problems, we propose an efficient Identity-Based conditional privacy-preserving authentication protocol, which does not rely on the ideal TPD. In our scheme, the System Secret Key (SSK) is not directly preloaded with the TPD, thus avoiding a system crash when a vehicle is corrupted. To revoke malicious vehicles’ identity, we propose an efficient key updating method based on Shamir’s secret sharing algorithm, which improves key-update efficiency from linear to logarithmic in the number of unrevoked vehicles. Moreover, our scheme is based on Elliptic Curves Cryptosystem and avoids bilinear pairing operation while supporting batch verification, enabling faster verification even when the number of signatures is increasing. According to the results of exhaustive comparative analysis, our proposed scheme is secure against key leakage attack and efficient in overhead of computation and communication compared to related schemes.

A blockchain-based conditional privacy-preserving authentication scheme for edge computing services

Edge computing is a new paradigm, especially suitable for Internet of Things (IoT) applications, which require low latency, location awareness and mass connections. It surely makes up for some shortcomings in cloud computing in terms of energy consumption and real-time analysis areas. However, it is still a great challenge to guarantee data security and privacy protection in edge computing environment. In this paper, we focus on the topic of authentication in edge computing and propose a conditional privacy-preserving authentication scheme based on blockchain, which guarantees user anonymity, conditional traceability as well as multi-factor security. The scheme uses elliptic curve cryptography (ECC) and does not use bilinear pairing operations. The key materials are stored on the blockchain and managed by the smart contracts. Formal security proof and heuristic security analysis show that the protocol satisfies desired security requirements and resists against most kinds of conventional attacks. Moreover, the performance comparison shows that the proposed scheme is more efficient in computation and communication than previous related schemes.

An Efficient Conditional Privacy-Preserving Authentication Protocol Based on Generalized Ring Signcryption for VANETs

With the rapid development of the Internet of Things (IoT), vehicular <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ad hoc</i> networks (VANETs) have gradually become a research hotspot. A number of Conditional Privacy-preserving Authentication (CPPA) schemes have been proposed to protect the security and privacy of the VANETs communication. However, most of them can only provide one function between signature and signcryption, making it difficult to meet the needs of complex application scenarios. Moreover, the majority of CPPA schemes allow a Trusted Authority (TA) to expose the malicious message's sender, but they can hardly prove the authenticity of the tracking result. Therefore, we propose a new CPPA protocol to solve these problems. In our protocol, generalized ring signcryption is introduced to provide ring signature mode and ring signcryption mode in one algorithm to satisfy the different security requirements in complex application scenarios. A convenient public verification algorithm is designed to make the tracking result provable and more credible. Furthermore, we prove that our protocol achieves confidentiality, unforgeability, and Known Session-Specific Temporary Information Security (KSSTIS). We also introduce pseudonyms in our protocol to resist the ring selection attack. The performance analysis shows that our protocol has at least 61.84% improvement in computational cost compared with several similar schemes.