Amid the rapid development of e-commerce and logistics, enterprises urgently require advanced digital technologies to achieve modernization and intelligent transformation, thereby meeting the fast-changing market demands. Within the logistics Internet of Things (IoT), companies face numerous scenarios that necessitate quantifying the degree of data overlap, where only acquiring statistical information suffices. The Private Set Intersection Cardinality (PSI-CA) technology offers an almost ideal solution. However, an effective approach must not only safeguard privacy but also enable companies to demonstrate their data protection capabilities to consumers. Existing PSI-CA solutions neglect the sustainable development needs of enterprises in terms of data correctness, integrity, management transparency, and user retention. Therefore, this paper proposes, for the first time, a trackable and verifiable authorized cloud-assisted PSI-CA (TVACPSI-CA) protocol, upon which a multi-threaded intelligent logistics system (ILS) is designed to harmonize data privacy protection with operational efficiency in logistics enterprises. The protocol employs accumulators, oblivious pseudorandom function (OPRF), zero-knowledge proof, digital signatures and blockchain technology to achieve objectives such as data privacy protection, access control, correctness verification of delegated computation, data integrity protection, abuse resistance, and traceability. This facilitates enterprises in mitigating security risks and enhancing customer trust. We rigorously analyze and prove the security of our solution. Finally, a comparative analysis with existing approaches demonstrates that the proposed scheme balances between high security and low communication/computational overhead. This provides the logistics industry with a secure, efficient, and scalable data-sharing solution, thereby enabling operational optimization.

The Internet of Things has been applied in various fields of industry, which has promoted the intelligent development of the industry and improved efficiency in industrial production. The devices involved in the IoT have generated useful and sensitive data over time and upload the data to the cloud to realize real-time data sharing. To ensure the confidentiality of data, many systems use attribute-based encryption primitive to encrypt data. However, there are still some security and privacy problems in this mode, such as the lack of identification of malicious users who leaked private keys, performance bottleneck caused by excessive reliance on a single central authority (CA), and vulnerability because a single CA holds the private keys of all users in the system. In this article, white-box tracking is used to identify malicious users. The alliance chain is introduced to support multiauthority environments, where the consensus nodes are managed by different authorities and assist CA in generating partial private keys. To protect users’ privacy, users remain anonymous at all times during their interactions with blockchain consensus. The security analysis and simulation results show that the proposed scheme outperformed other comparable schemes, indicating that it is a preferable scheme.

The application of 5G makes the medical Internet of Things(IoMT) bring many opportunities to the medical industry. It is expected to improve the quality and efficiency of medical services and improve people’s quality of life. However, a large number of data and users are generated by smart devices in IoMT. How to access and share securely the dynamic data and manage the dynamic users has been a challenging problem at present. Many various methods were introduced to solve it. However, collusion attacks, privacy leakage, and high computational costs are not solved or only partly solved. In this paper, we analyze the most recent work at first and point out their drawbacks. Additionally, the user revocation method adopted by these schemes can not prevent revoked users from colluding with unrevoked users or the cloud to obtain shared data. Subsequently, we propose an efficient policy hiding and policy updating attribute-based data sharing scheme. The proposals support user revocation, which solves the collusion between the revoked users and unrevoked users or the cloud. Under this scheme, attributes are divided into attribute names and attribute values, and sensitive information attribute values are hidden in access policies to protect user privacy. We reduce user computational overhead by using outsourced techniques and policy update methods. The scheme is proved to be fully secure which is stronger than most of the existing works. The comparison and simulation results confirm the advantages of the proposed scheme over the available in the IoMT.

As an important component of the Industrial Internet of Things (IIoT), the smart factory uses IIoT and equipment-monitoring technology to collect data to reasonably arrange the production. A large number of data is collected and uploaded to the IIoT cloud platform. However, the IIoT cloud platform is semitrusted and has structural limitations and vulnerability, which makes it necessary to realize data dynamic security sharing and malicious users' tracking. In this article, we show that the most recent work on this issue is still vulnerable to security threats at first. Then, a blockchain-enabled dynamic and traceable data-sharing scheme for a smart factory is proposed. Blockchain performs the user authentication and stores the ciphertext index and public keys to avoid tampering with shared data. The tracking algorithm tracks malicious users and adds them to a revocation list embedded in the ciphertext. And the authority can flexibly select domain or user revocation as required. The LSSS access policy is hidden to protect user privacy, and the cloud server uses the match test algorithm to detect whether users meet the hidden access policy. Additionally, online–offline encryption and outsourced decryption improve the efficiency of the scheme where the ciphertext and the pairing operations required for decryption achieve constant size. A performance analysis shows that the scheme can resist a variety of collusion attacks, and simulations show that it outperforms current schemes.

Personal health records (PHRs) are located in a patient-centered electronic health system in which users can store and share medical information. However, PHRs have recently been plagued by security issues, such as the leakage of personal health information, illegal access to patient data, and data tampering. Recent security developments, such as introducing an access control policy with attribute-based encryption (ABE) or utilizing blockchain, have only been partially successful in solving these issues. Ongoing challenges to PHR sharing include single points of failure, node cheating attacks, and fair keyword search issues. In this article, we tackle these challenges by introducing a distributed PHR-sharing scheme based on blockchain and ciphertext policy ABE (CP-ABE), which allows for fast and efficient encryption and decryption. Blockchain maintains the integrity and the tracing source of the data while also recording all operations on the data in the form of transactions. In addition, the blockchain nodes act as attribute authorities to construct the CP-ABE cryptosystem. The tracing of malicious blockchain nodes is realized by tracing cryptography algorithms. Furthermore, the fair retrieval of ciphertext is achieved by employing smart contracts. To overcome the limited storage capacity of blockchain, we adopt both the on-chain and off-chain storage modes in our new system. Security analysis indicates that our new scheme remains intact when threatened by an indistinguishable chosen plaintext attack (IND-CPA) and an indistinguishable chosen keywords attack (IND-CKA). As such, we conclude that our proposed approach is feasible and efficient.

The vehicular social network (VSN) is an emerging mobile communication system combining a vehicle ad hoc network (VANET) with a social network. It provides a new means of sharing, disseminating, and delivering data for passengers, drivers, and vehicles. However, a VSN may expose users’ private information, such as identities, location information, and trajectories, and tampering with shared data may lead to security and safety problems in vehicle systems. Considering the security and privacy preservation of shared data, we propose a lightweight decentralized multiauthority access control scheme based on ciphertext-policy attribute-based encryption (CP-ABE) and blockchain, by which a decentralized multiauthorization node supports vehicle users by performing lightweight calculations with the assistance of the vehicle cloud service provider (VCSP). We use blockchain to record storage and access transactions, achieving self-verification by users and tamper-resistance of ciphertexts. An improved smart contract reduces the workload of verification by users and achieves privacy preservation by hiding the policy. It supports user revocation and outsourced decryption, enabling more flexibility and better performance. A security and performance analysis shows that our scheme has clear advantages over existing schemes.

We present a new construction of anonymous hierarchical identity-based encryption (HIBE) over prime order groups. The distinct feature of our proposed scheme is that both private key and ciphertext have a constant size, which has never been achieved in all other existing anonymous HIBE schemes. Moreover, we utilized a double exponent technique to generate the ciphertext in order to provide anonymity. This simple and efficient method allows us to construct a more compact anonymous HIBE in prime order groups. Under the decisional bilinear |$n+1$|-Diffie–Hellman exponent assumption and linear assumption, we show that the proposed scheme is secure and anonymous against chosen plaintext attacks in the standard model.

In this paper, a new construction of hierarchical ID-Based signature (HIBS) scheme is proposed. The new scheme has some advantages over the available schemes: the private keys size shrinks as the identity depth increases and the signature size is a constant as it consists of three group elements. Furthermore, under the h-CDH assumption, our scheme is provably secure in the standard model. This assumption is more natural than many of the hardness assumptions recently introduced to HIBS in the standard model.