In Vehicular Ad-hoc Networks (VANETs), the ability of emergency vehicles (EVs) to reach their destinations quickly can maximize the protection of people’s lives and property safety, and minimize the losses and impacts caused by various emergencies. In this endeavor, the emergency vehicle avoidance protocol is of paramount importance. However, the existing authentication protocol is vulnerable to side-channel attacks, Roadside Units (RSUs) captured attacks, as well as untraceability, etc. Therefore, for wider and more practical realizability, we propose an efficient and secure authentication scheme based on Elliptic Curves Cryptography (ECC), fuzzy extraction algorithm and Physical Unclonable Function (PUF) for EVs avoidance. In the protocols, PUF and biometric key are used for protecting RSUs’ and EVs’ privacy information respectively. Additionally, a conditional privacy-preserving and traceable message authentication strategy is designed for emergency messages propagation, the avoidance messages can be forwarded to ordinary vehicles before the EVs arriving. Compared with related EVs avoidance protocols, our protocol can resist side-channel attacks and other various known attacks. In our scheme, the first authentication efficiencies have increased by 11.72% and the subsequent authentication increased by 25.99% than the previous protocols in the same scenario. Security and performance analysis demonstrate that the proposed scheme is secure, efficient, and practical.

Real-time performance is of utmost significance for communication in certain specific scenarios of vehicle-to-infrastructure (V2I) like collision warning systems. Vehicle-to-Everything (V2X) Broadcast signcryption is very suitable for these scenarios. However, current solutions prioritize generality, but may not be suitable for specialized communication situations, and many broadcast signcryption schemes suffer from low communication verification efficiency due to the sequence of decryption before verification. Moreover, most of existing broadcast signcryption schemes with single cryptosystem are not applicable for the heterogeneous networks of different Internet of Vehicles. To address these challenges, an efficient conditional privacy-preserving heterogeneous broadcast signcryption scheme(ECPHBS) is proposed, improving roadside unit verification to support batch verification of ciphertexts through a pre-authentication mechanism, and allowing vehicles to conduct secure communication with roadside units under the certificateless cryptosystem and the identity-based cryptosystem. Meanwhile, a tracking and revocation mechanism was introduced to achieve conditional privacy protection. Our formal security analysis demonstrates that the ECPHBS scheme formally achieves IND-CCA2 security under the CDH assumption and EUF-CMA security under the ECDL problem. Experimental results confirm its superior verification efficiency, especially with an increasing number of receiving RSUs, and a constant communication overhead. Furthermore, the RSU service capability analysis shows that our scheme enables RSUs to fully handle communication requests from approximately 500 vehicles within a 150-meter range, outperforming comparative schemes.

Cloud computing has become an essential paradigm for facilitating large-scale and privacy-preserving encrypted image retrieval in Internet of Things (IoT) environments. However, existing encrypted image retrieval schemes face challenges in balancing retrieval efficiency and data security, which hinders their practical adoption. On one hand, retrieval-efficient schemes based on secure k-Nearest Neighbor (kNN) are prone to known-plaintext attacks; on the other hand, highly secure schemes based on homomorphic encryption often suffer from excessive computational and storage overhead. Furthermore, supporting multi-user environments and enforcing fine-grained access control over query users are critical challenges in IoT-based retrieval systems. To tackle these issues, we propose a Secure and Controllable similarity Retrieval scheme in Multi-user settings (SCRM), which achieves a practical trade-off between efficiency and security while enabling multi-user management. First, we design an efficient and privacy-preserving similarity computation method that is resilient against known-plaintext attacks. Second, we introduce a key conversion protocol that enables similarity retrieval in multi-user settings without requiring key sharing. Third, we integrate attribute-based encryption to enforce fine-grained access control and trace query users who may leak decryption keys. A correctness analysis confirms that SCRM ensures accurate similarity retrieval while supporting access control. Furthermore, a formal security analysis demonstrates that SCRM effectively protects data privacy against known-plaintext attacks. Finally, extensive experiments on real-world image dataset validate the efficiency and effectiveness of SCRM.

Privacy-preserving similarity retrieval for ciphertext images has broad applications in Internet of Things (IoT) areas, including smart healthcare, face recognition, and social networking. However, most existing privacy-preserving schemes suffer from inefficient retrieval and limited security guarantees due to the use of unreasonable encryption methods. In addition, those supporting fine-grained access control often lack scalability or are computationally inefficient. To address these challenges, we propose an efficient similarity retrieval scheme for ciphertext images that ensures both privacy preservation and fine-grained access control. First, we construct an encrypted index tree using clustering to improve retrieval efficiency while preserving high recall. Second, we achieve security against chosen-plaintext attacks (CPA) and result verification by employing symmetric homomorphic encryption and Merkle hash tree. Third, we realize access control for each image, enabling simultaneous access verification and similarity retrieval via a single inner product operation. Our theoretical and experimental analysis shows that the proposed scheme is CPA-secure and achieves up to 100× faster query processing than existing CPA-secure schemes, with the ability to retrieve 2000 ciphertext images within 0.5 seconds for 128-dimensional feature vectors.

Internet of Medical Things-based healthcare system (IoMTHS) is a kind of industrial information system that integrates life monitoring, pathological inference and drug therapy. However, the sensitive nature and high value of its data make it a prime target for cyberattacks. Although many multiserver authentication protocols have been studied in recent years to ensure that only authorized users can access medical services, new vulnerabilities are always identified and covertly utilized by the smarter adversary due to lack of continuous monitoring and dynamic authentication, reducing the trustworthiness of IoMTHS. To address above challenges, in this article, we propose a multiserver authentication scheme with integrated monitoring (MAIM) for IoMTHS, which achieves user locked access control by strictly and continuously binding system access permissions and user behavior. MAIM consists of a three-factor-based static authentication (TFSA) and a deep learning-based continuous authentication (DLCA). TFSA utilizes double-anonymity strategy to protect users’ privacy and track their malicious behaviors, and uses physical unclonable function (PUF) to protect the security of privacy information in users’ devices and servers, which achieves lightweight and three-factor secrecy. The DLCA trains a deep neural network to recognize the legitimacy of users based on the user behavior transmitted by their sensing devices. TFSA is provably secure under the random oracle model, whereas DLCA exhibits high feasibility with experimental accuracy reaching 100%.

Matchmaking encryption constructed in the identity-based encryption setting, named identity-based matchmaking encryption (IB-ME), requires both sender and receiver to specify target identity simultaneously for each other for message decryption. The IB-ME schemes can not only ensure the privacy of the sender and the message but also provide authentication for the data source. In order to resist quantum-attacks, we put forward a post-quantum secure IB-ME scheme. Compared with Ateniese et al.'s scheme and Francati et al.'s scheme, our approach eliminates the use of functional encryption, predicate encryption and signature scheme, and only uses a more simple preimage sampling function and an IBE scheme in the way of non-black-box. Compared with post-quantum secure IB-MEs proposed currently, our scheme is the first non-black-box construction based on standard lattice assumptions such as LWE and ISIS.

To address the challenges encountered by dictionary learning-based monitoring, this article presents a novel pattern discovery scheme for detection and isolation of incipient faults that involves structured sparse coding and sequential dictionary augmentations. Through learning a basic dictionary for normal pattern and augmenting the low-dimensional sparse dictionaries for analyzing different fault patterns, the process signals can be decomposed into fault-free and fault-related components. To guarantee the in-statistical-control status of the fault-free part and improve detection sensitivity, a$\ell _{2}$-penalty is imposed on the sum of coefficient vectors to ensure that the monitoring statistic related to the fault-free part will not exceed the control limit. In addition, two Frobenius norm penalties are imposed on the zero centered coefficient matrix and atom matrix to improve the robustness of signal decomposition. Instead of imposing$\ell _{1}$-sparsity constraint on the atoms, a hard sparsity constraint is used to correctly select fault-related feature variables, so that fault patterns can be better revealed. The informative dictionaries are then incorporated into the moving window-based monitoring strategy, yielding a fault detection and isolation scheme suitable for incipient faults. The superior performance of our proposed approach is validated by application studies involving a numerical example and two practical industrial processes.

In vehicular ad-hoc networks (VANETs), existing traffic accident handling schemes are adoptable only in the scenario with roadside unit (RSU) deployment, and the generation of accident reports relies on RSUs and witness vehicles. Without the confirmation from involved vehicles in the accident, it will probably cause disputes afterward, and RSU captured attacks may also affect authentication of vehicles and correctness of accident reports. To address the above issues, we propose a vehicle to vehicle (V2V) and vehicle to RSU (V2R) authentication and traffic accident handling protocol, in which accident vehicles are sufficient to generate accident reports, thereby enhancing autonomy of the vehicular communication system and reducing reliance on external infrastructure. Furthermore, for ensuring integrity and traceability of accident reports, we utilize blockchain to keep registration information and jointly signed reports, which realizes efficient and secure mutual authentications in V2V and V2R protocols. Finally, for preserving privacy of vehicles, we integrate elliptic curve cryptosystem (ECC) and symmetric encryption to design a dynamic pseudo-identity strategy, which still allows the registration center to track malicious vehicles. The formal security proof and comparative analysis validate that our protocol preserves higher security and lower overhead by comparison with related schemes.

To ensure the secure access control mechanisms for the wireless sensor networks (WSN) with a 5G-enabled IoT system, very recently, Sahoo et al. (IEEE Internet of Things Journal, 10(17), pp. 15087-15099, DOI: 10.1109/JIOT.2023.3264565, Sep. 1, 2023) proposed a three-factor-based authentication scheme of 5G WSN for IoT system, and claimed that their scheme can achieve all security properties. However, in this paper, we carefully analyze their scheme and point out that their scheme is vulnerable to user impersonation attacks, sensor node captured attacks, simultaneous impersonation attacks on the gateway and sensor node, and cannot achieve user unlinkability and three-factor secrecy, and an adversary can obtain the encrypted data sent from the sensor node, and can also forge the encrypted data. In addition, we analyze the reasons why their scheme suffers from these attacks and propose the remedial suggestions.

Ensuring trust within the healthcare system and addressing privacy and security challenges in the Internet of Medical Things (IoMT) is of paramount importance. Based on our preliminary analysis results of Masud et al.’s authentication protocol, we propose an improved solution building upon their protocol. Our improved protocol incorporates various security measures to enhance its security. To validate the effectiveness of our improved protocol, we employ a comprehensive range of heuristic and formal security analysis methods. Comparative evaluations with other relevant protocols reveal that our proposed solution achieves satisfactory operational performance in resource-constrained IoMT scenarios.

This letter addresses some security issues of an identity-based provable data possession protocol with compressed cloud storage (published in IEEE TIFS, doi:10.1109/TIFS.2022. 3159152). Some serious flaws are identified and an attack to the protocol is designed. This attack is able to recover the ephemeral secret keys from two encrypted blocks with high probability to reveal the original plaintext file completely. Moreover, an adversary can impersonate a data owner to outsource any file to the cloud in a malicious way. The main ingredients of the attack is some classical number theoretic results.

Industrial Internet of Things (IIoT) is revolutionizing plenty of industrial applications by utilizing large-scale smart devices in manufacturing and industrial processes. However, IIoT is facing the disclosure of identity privacy. The identity information is precious and critical, thereby inspiring a line of follow-up privacy-preserving studies, i.e., anonymous credential protocols, or privacy-preserving identity management schemes. However, they are either too anonymous to be used in the IIoT environment, or the system is highly centralized, which implies the risk of a single point of failure. In this article, we proposePBidm, a privacy-preserving blockchain-based identity management scheme for IIoT. Specifically, by leveraging blockchain and diversified cryptographic tools,PBidmcan fully support the desirable properties, i.e., unforgeability, blindness, unlikability, traceability, revocability, and public verifiability. Then, we provide security analysis to ensure reasonable security assurance. Finally, we present a performance evaluation of the proposed scheme to demonstrate the practicability in IIoT applications.

Vehicular Ad-hoc Networks (VANETs) enable the connection and information exchange between vehicles and transportation infrastructure (V2I), vehicle and vehicle (V2V) to improve the safety and efficiency of the transportation system. In previous protocols, V2I and V2V authentication protocols based on bilinear pairings or identity-based cryptography are computationally heavy or difficult to protect the user’s identity and privacy. In addition, lightweight authentication protocols have not achieve both V2I and V2V authentication, and may suffer from Onboard Unit (OBU) intrusion attacks, Roadside Unit (RSU) captured attacks, and difficult to track malicious vehicles. Therefore, a lightweight and anonymous V2I and V2V authentication protocol with batch verification based on Elliptic Curves Cryptography (ECC) is proposed. We use Physical Unclonable Function (PUF) and biological key to avoid RSU captured attacks and OBU intrusion attacks, design a feature embedding strategy with dynamic pseudo-identity to recover the malicious vehicle’s identity by the Trusted Authority (TA). In the application test simulating the actual scenario, our protocol is more efficient because of lower overhead and batch authentication strategy. The semantic security of the protocol is formally proved under the random oracle model. The comparative analysis and security proof results show that our protocol is more superior to others.

The Internet of things is playing more and more important role in smart healthcare, smart grids, and smart transportation, and using wireless sensor network (WSN), we can easily obtain and transmit information. However, the data security and users’ privacy are the biggest challenges for WSN because sensor nodes have low computing power and low storage capacity and are easy to be captured, and wireless networks are vulnerable. In 2021, Shuai et al. proposed a lightweight three-factor anonymous authentication scheme for WSN. However, we found that their protocol is vulnerable to stolen-verifier attack, modification of messages’ attack, and no perfect forward secrecy. Then, a new three-factor anonymous authentication scheme using elliptic curve cryptography (ECC) is proposed. Through informal and formal security analyses, our scheme can resist various known attacks and maintains low computational complexity.

Authenticated key exchange (AKE) protocol allows a user and a server to authenticate each other and generate a session key for the subsequent communications. With the rapid development of low-power and highly-efficient networks, such as pervasive and mobile computing network in recent years, many efficient AKE protocols have been proposed to achieve user privacy and authentication in the communications. Besides secure session key establishment, those AKE protocols offer some other useful functionalities, such as two-factor user authentication and mutual authentication. However, most of them have one or more weaknesses, such as vulnerability against lost-smart-card attack, offline dictionary attack, de-synchronization attack, or the lack of forward secrecy, and user anonymity or untraceability. Furthermore, an AKE scheme under the public key infrastructure may not be suitable for light-weight computational devices, and the security model of AKE does not capture user anonymity and resist lost-smart-card attack. In this paper, we propose a novel dynamic ID-based anonymous two-factor AKE protocol, which addresses all the above issues. Our protocol also supports smart card revocation and password update without centralized storage. Further, we extend the security model of AKE to support user anonymity and resist lost-smart-card attack, and the proposed scheme is provably secure in extended security model. The low-computational and bandwidth cost indicates that our protocol can be deployed for pervasive computing applications and mobile communications in practice.

In this paper, we present a new identity-based encryption IBE scheme using bilinear pairings. Compared with the famous IBE scheme of Boneh and Franklin, ours is more practical in the multiple private key generator multiple-PKG environment. We prove that our scheme meets chosen ciphertext security in the random oracle model, assuming the intractability of the standard bilinear Diffie-Hellman problem. Copyright © 2013 John Wiley & Sons, Ltd.

SUMMARY In 2009, Wu and Lin introduced the concept of self‐certified proxy convertible authenticated encryption (SP‐CAE) by integrating self‐certified public‐key system and designated verifier proxy signature with message recovery. They also presented the first SP‐CAE scheme which is based the discrete logarithm problem. However, Wu‐Lin scheme is not secure as Xie et al. recently showed that this scheme is existentially forgeable under adaptive chosen warrants, unconfidentiable and verifiable under adaptive chosen messages and designated verifiers. In this paper, we first discuss the security requirements of SP‐CAE and then formally define unforgeability, message confidentiality, and unverifiability. Consequently, the first complete formal model of SP‐CAE is proposed. After that, we propose a provably secure SP‐CAE scheme by using two‐party Schnorr signature introduced by Nicolosi et al. in 2003. Finally, we prove the formal security of the proposed scheme in the random oracle model under the discrete logarithm assumption. Copyright © 2013 John Wiley & Sons, Ltd.

ABSTRACT Recently, Chen et al. proposed a practical authentication protocol for supporting anonymous roaming in wireless access networks, then the protocol is further improved by Hsieh and Leu. In this paper, we demonstrate the adversarial model of this type of protocols and show that Hsieh‐Leu scheme is not as secure as they originally claimed to be. In particular, we show that their protocol does not provide user privacy protection, and it is vulnerable to off‐line password guessing attack mounted by a side channel adversary who has compromised all the information stored in the user's smart card. To fix these weaknesses, a new practical authentication protocol with anonymity for wireless roaming is proposed. We use the formal verification tool ProVerif, which is based on applied pi calculus, to prove the security of the proposed scheme. The experimental results confirm that the new scheme not only achieves many desirable properties, such as strong anonymity, perfect forward secrecy and support of session key update, but also provides robustness against all those attacks that Hsieh–Leu protocol does not resist. Copyright © 2013 John Wiley & Sons, Ltd.

Single sign-on (SSO) is a new authentication mechanism that enables a legal user with a single credential to be authenticated by multiple service providers in a distributed computer network. Recently, Chang and Lee proposed a new SSO scheme and claimed its security by providing well-organized security arguments. In this paper, however, we demonstrative that their scheme is actually insecure as it fails to meet credential privacy and soundness of authentication. Specifically, we present two impersonation attacks. The first attack allows a malicious service provider, who has successfully communicated with a legal user twice, to recover the user's credential and then to impersonate the user to access resources and services offered by other service providers. In another attack, an outsider without any credential may be able to enjoy network services freely by impersonating any legal user or a nonexistent user. We identify the flaws in their security arguments to explain why attacks are possible against their SSO scheme. Our attacks also apply to another SSO scheme proposed by Hsu and Chuang, which inspired the design of the Chang–Lee scheme. Moreover, by employing an efficient verifiable encryption of RSA signatures proposed by Ateniese, we propose an improvement for repairing the Chang–Lee scheme. We promote the formal study of the soundness of authentication as one open problem.