Search Results (33)

Key agreement in open networks must not only resist quantum computing threats but also establish keys and authenticate counterparties without explicitly revealing identities. Existing solutions often rely on additional certificates or explicit signature-based authentication or require multiple rounds of interaction and complex state management, thereby imposing burdens on deployment and scalability. To address this, we propose a key agreement protocol based on a post-quantum identity-matching scheme, which unifies identity binding, implicit authentication, and session key establishment into a single key agreement process. Specifically, the initiator generates a ciphertext based on the peer’s identity and embeds session-related information within it, enabling the recipient to verify the peer’s identity and confirm the consistency of the key while decrypting and recovering the shared material. Additionally, bidirectional confirmation messages are used to eliminate negotiation deviations such as the sharing of unknown keys. Furthermore, a version control mechanism is introduced as a synchronization tag for key evolution, allowing the session key to be naturally updated within a predetermined time window. Concurrently, a revocation list maintained by a blockchain is established, enabling distributed verification and auditing of revocation status. This supports key update and revocation management without increasing the number of negotiation rounds. Performance evaluations and security analyses indicate that the protocol incurs a single-end computational overhead of less than 100 μs and a communication overhead of approximately 17.1 KB, trading moderate performance overhead for strong security semantics. Full article

The dynamic nature of Vehicular Ad-hoc Networks (VANETs) necessitates robust authentication mechanisms to prevent adversaries from compromising vehicle privacy. To address privacy concerns, many existing approaches employ pseudonyms in place of real vehicle identities. However, the use of a single pseudonym is insufficient, as vehicle trajectories can still enable tracking. Consequently, vehicles must frequently change pseudonyms, typically selecting them from a pre-assigned pool, to ensure unlinkability and preserve privacy. In most existing schemes, a central authority issues certificates corresponding to each pseudonym, which vehicles present for authentication. While effective, this approach incurs significant computation, storage, and communication overhead, particularly in managing certificate revocation lists (CRLs), since each vehicle may possess a large number of pseudonyms. To address these challenges, we propose a Low-overhead and Efficient Privacy-preserving Authentication (LEPA) scheme for VANETs, leveraging Merkle Hash Trees (MHTs) and Cuckoo Filters (CFs) to efficiently manage pseudonym sets and revocation. We analyze the security of the proposed scheme against various attacks and demonstrate, through performance evaluation, that LEPA significantly reduces authentication and revocation overhead while maintaining strong privacy and security guarantees. Full article

As an important achievement in agricultural sci-tech innovation, gene-edited animals are not only a basic element for rural revitalization but also the core of promoting the biological breeding industry. Exploring their supervision models and institutional construction is practically significant and supports new productive forces in agriculture. Currently, various research and development achievements have emerged, but China lacks clear legal norms for their transformation and food industry supervision, failing to meet modern breeding needs. Internationally, three main supervision models (strict, open, eclectic) are determined by each country’s technological level, legal soundness and public acceptance. To build China’s sui generis supervision system for gene-edited animals that is independent of both GM animals and gene-edited plants, top-level design should issue categorized supervision policies to clarify research and development and industrialization norms, including relevant principles and procedures; establish a pre-positive ethical review mechanism with strict animal welfare checks; set animal welfare damage as a certification revocation condition; build a traceability platform for gene-edited animals and their products; implement positive food labeling; strengthen public participation to balance technological innovation and risk prevention; safeguard biosafety and public interests; and provide legal support for industrialization of gene-edited animals. Full article

With the rapid development of the Internet of Medical Things (IoMT), the data generated and collected by various sensors and medical devices are gradually increasing. How to realize flexible, efficient, and secure data sharing while ensuring data confidentiality and patient privacy has become a critical research challenge. The traditional Public Key Infrastructure (PKI) must deal with the complicated certificate management problem. An identity-based cryptosystem has the inherent key-escrow risk. These concerns make them unsuitable for resource-constrained and dynamic IoMT environments. To address it, this paper introduces a cloud data sharing protocol for IoMT using a Certificateless Proxy Re-encryption (CL-PRE) scheme that integrates an efficient access-list-based user revocation mechanism. In our system, a patient’s data can be encrypted and securely stored in a semi-trusted third party like the cloud server. When the patient wants to grant the access to designated users, e.g., doctors or medical institutions, a delegated proxy server will re-encrypt the ciphertext to a new one, which is decryptable by the designators. The proxy server also learns nothing during the re-encryption process, so as to maintain the end-to-end confidentiality. As for the security, the authors formally prove that the proposed CL-PRE mechanism for IoMT achieves Type-I and Type-II indistinguishability against adaptive chosen-identity and chosen-ciphertext attacks (IND-PrID-CCA) under the Decisional Bilinear Diffie–Hellman (DBDH) assumption. Moreover, the functional and computational comparisons with previous studies reveal the qualitative advantage of simultaneously achieving certificateless properties and user revocation, and the quantitative advantage of an optimized encryption cost (requiring only one bilinear pairing and two scalar multiplications), making it a theoretically efficient solution for resource-constrained IoMT devices. Full article

This paper presents a certificateless group signature scheme designed specifically for Unmanned Aerial Vehicle (UAV) communications in resource-constrained environments. The scheme leverages Physical Unclonable Functions (PUFs) and elliptic curve cryptography (ECC) to provide a lightweight security solution while maintaining essential security properties including anonymity, unforgeability, traceability, and unlikability. We describe the cryptographic protocols for system setup, key generation, signing, verification, and revocation mechanisms. The implementation shows promising results for UAV applications where computational resources are limited, while still providing robust security guarantees for group communications. Our approach eliminates the need for computationally expensive certificate management while ensuring that only legitimate group members can create signatures that cannot be linked to their identities except by authorized group managers. Full article

We introduce TrustShare, a novel blockchain-based framework designed to enable secure, privacy-preserving, and trust-aware cyber threat intelligence (CTI) sharing across organizational boundaries. Leveraging Hyperledger Fabric, the architecture supports fine-grained access control and immutability through smart contract-enforced trust policies. The system combines Ciphertext-Policy Attribute-Based Encryption (CP-ABE) with temporal, spatial, and controlled revelation constraints to grant data owners precise control over shared intelligence. To ensure scalable decentralized storage, encrypted CTI is distributed via the IPFS, with blockchain-anchored references ensuring verifiability and traceability. Using STIX for structuring and TAXII for exchange, the framework complies with the GDPR requirements, embedding revocation and the right to be forgotten through certificate authorities. The experimental validation demonstrates that TrustShare achieves low-latency retrieval, efficient encryption performance, and robust scalability in containerized deployments. By unifying decentralized technologies with cryptographic enforcement and regulatory compliance, TrustShare sets a foundation for the next generation of sovereign and trustworthy threat intelligence collaboration. Full article

Current authentication schemes based on zero-knowledge proof (ZKP) still face issues such as high computation costs, low efficiency, and security assurance difficulty. Therefore, we propose a secure and efficient authentication scheme (SEAS) for large-scale IoT devices based on ZKP. In the initialization phase, the trusted authority creates prerequisites for device traceability and system security. Then, we propose a new registration method to ensure device anonymity. In the identity tracing and revocation phase, we revoke the real identity of abnormal devices by decrypting and updating group public keys, avoiding their access and reducing revocation costs. In the authentication phase, we check the arithmetic relationship between blind certificates, proofs, and other random data. We propose a new anonymous batch authentication method to effectively reduce computation costs, enhance authentication efficiency, and guarantee device authentication security. Security analysis and experimental results show that an SEAS can ensure security and effectively reduce verification time and energy costs. Its security and performance exceed existing schemes. Full article

In the current 5G vehicle network system, there are security issues such as wireless intrusion, privacy leakage, and remote control. To address these challenges, an improved lightweight anonymous authentication key negotiation scheme based on certificate-less aggregate signatures is proposed and its security and efficiency are analyzed. The result shows that the scheme can offer security attributes including anonymity, traceability, and revocability, as well as effective identity authentication, and it can resist forgery attacks, man-in-the-middle attacks, tampering attacks, and smart card loss attacks. Moreover, compared with similar schemes, it possesses superior security and more efficient computational efficiency and less communication overhead, thereby being more appropriate for high-speed, large-capacity, low-latency, and resource-constrained 5G vehicle network application scenarios. Full article

Authentication is a crucial security service on the Internet. In real-world applications, multiple independent trust domains often exist, with each recognizing only certain identities within their own systems. During cross-domain access, users cannot directly use their original certificates, which presents a cross-domain authentication problem. Traditional centralized schemes typically employ a trusted third party (TTP) to facilitate the transfer of identity trust across domains. These schemes inevitably inherit the vulnerabilities associated with single points of failure. In contrast, blockchain-based decentralized schemes effectively eliminate the potential threats posed by TTPs. However, the openness and transparency of the blockchain also bring new security issues, such as privacy leakage. In this paper, we propose a zk-SNARK-based anonymous scheme on the blockchain for cross-domain authentication. Specifically, our scheme adopts an authorization-then-proof structure, which strikes a delicate balance between anonymity and revocability. We provide theoretical proofs for the security of our scheme and explain how it achieves proactive revocability. Experimental evaluation results demonstrated that our scheme is both secure and efficient, and the revocation could be accomplished by introducing only 64 bytes of on-chain storage with one hash comparison. Full article

Team score orienteering, a challenging and interesting sport, is gradually becoming known by the majority of sports enthusiasts. Integrating team score orienteering with the Internet can enhance the interactive experience for athletes. However, this integration increases the risk of the leakage of the athletes’ information. In order to protect the privacy of athletes, it is necessary to employ encryption. Therefore, this paper proposes an efficient lattice-based revocable certificateless public key encryption (RCL-PKE) scheme with decryption key exposure resistance (DKER). The adoption of certificateless encryption not only avoids the complex certificate management required for traditional public key encryption, but also addresses the key escrow problem of identity-based encryption, thereby significantly ensuring data security and privacy. Furthermore, the revocable mechanism enables the organizing committee to flexibly manage the athletes’ qualification for competitions, and DKER can effectively prevent the leakage of decryption keys, which further enhances data security. The constructed RCL-PKE scheme was proven to be IND-CPA secure under the learning with errors (LWE) assumption. Experiments indicated that the proposed RCL-PKE scheme had lower computation and communication costs, making it particularly suitable for team score orienteering. Full article

Ensuring security in electronic examination systems represents a significant challenge, particularly when practical considerations dictate that most involved parties cannot be fully trusted due to self-interest. To enhance the security, we introduce auditability to e-exam systems, enabling an auditing authority to verify the system integrity. This auditability not only ensures system robustness but also creates an opportunity to grant communication between candidates and examiners, allowing for clarification on unclear questions during exams. Additionally, the implementation of attribute-based certifications ensures anonymity for both candidates and examiners throughout all stages of the exam, with the option for revocation in case of audit-detected fraud. Full article

Internet applications rely on Secure Socket Layer (SSL)/Transport Security Layer (TSL) certifications to establish secure communication. However, the centralized nature of certificate authorities (CAs) poses a risk, as malicious third parties could exploit the CA to issue fake certificates to malicious web servers, potentially compromising the privacy and integrity of user data. In this paper, we demonstrate how the utilization of decentralized certificate verification with blockchain technology can effectively address and mitigate such attacks. We present a decentralized public key infrastructure (PKI) based on a distributed trust model, e.g., Web of Trust (WoT) and blockchain technologies, to overcome vulnerabilities like single points of failure and to prevent tampering with existing certificates. In addition, our infrastructure establishes a trusted key-ring network that decouples the authentication process from CAs in order to enhance secure certificate issuance and accelerate the revocation process. Furthermore, as a proof of concept, we present the implementation of our proposed system in the Ethereum blockchain, confirming that the proposed framework meets the five identified requirements. Our experimental results demonstrate the effectiveness of our proposed system in practice, albeit with additional overhead compared to conventional PKIs. Full article

Log-based public key infrastructure(PKI) refers to a robust class of CA-attack-resilient PKI that enhance transparency and accountability in the certificate revocation and issuance process by compelling certificate authorities (CAs) to submit revocations to publicly and verifiably accessible logs. However, log-based PKIs suffer from a reliance on centralized and consistent sources of information, rendering them susceptible to split-world attacks, and they regrettably fail to provide adequate incentives for recording or monitoring CA behavior. Blockchain-based PKIs address these limitations by enabling decentralized log audits through automated financial incentives. However, they continue to face challenges in developing a scalable revocation mechanism suited for lightweight clients. In this paper, we introduce BRT, a scalable blockchain-based system for certificate and revocation transparency. It serves to log, audit, and validate the status of certificates within the transport layer security (TLS)/secure sockets layer(SSL) PKI domain. We designed an audit-on-chain framework, coupled with an off-chain storage/computation system, to enhance the efficiency of BRT when operating in a blockchain environment. By implementing a blockchain-based prototype, we demonstrate that BRT achieves storage-efficient log recording with a peak compression rate reaching 8%, cost-effective log updates for large-scale certificates, and near-instantaneous revocation checks for users. Full article

This paper addresses the certificate revocation problem and proposes the first revocable pairing-based signature scheme with implicit and explicit certificates (IE-RCBS-kCAA). We should no longer discuss whether to revoke certificates but how to do it effectively, ensuring both the scalability of the revocation operation and the non-repudiation of the signature in the short or long term. Under the computational difficulty assumptions of the modified collusion attack algorithm with k traitors (k-mCAA) and discrete logarithm (DL) problems, we demonstrate that our scheme is secure against existential unforgeability under chosen message attacks (EUF-IERCBS-kCAA-CMA) in a random oracle model. The proposed solution is scaled and allows the use of many trusted status authorities that issue explicit short-term certificates confirming the validity of explicit long-term certificates. Furthermore, we demonstrate that our signature scheme has a short-term non-repudiation property for the shell validity model. Full article

Underwater Wireless Sensor Networks (UWSNs) obtains more attention due to their wide range of applications such as underwater oil field discovery, Tsunami monitoring systems, surveillance systems, and many more. In such a resource-constrained environment, sensors are more vulnerable to malicious attacks. Node authentication and secure communication is one of the vital issues in UWSNs. In this study, a secure and lightweight key management framework for UWSNs is proposed. The proposed framework includes key generation, key distribution, revocation, and authentication mechanisms along with lightweight implementation, and scalability. We use an elliptic curve-based algorithm for key distribution, and certificate revocation list (CRL) for key revocation. We also examine the performance of the proposed framework taking into account the amount of communication overhead as well as the level of security. The simulation results show that the proposed framework provides better security with less communication overhead compared to existing frameworks. This framework can be used for secure data communication in UWSNs, which has various applications in oceanography, environmental monitoring, and military operations. Full article