With the development of cloud computing and the digital transformation of the medical industry, the application scenarios and effects of smart healthcare are constantly expanding and improving. Smart healthcare plays an important role in improving service quality and medical efficiency and reducing medical costs. However, in the process of data collection, storage, and transmission, the risk of patients’ privacy being illegally accessed or leaked has become increasingly prominent. These medical data contain sensitive information about patients, and once leaked, it will violate the privacy of patients, cause medical accidents, and seriously damage the legitimate rights and interests of patients. An efficient and reliable privacy protection mechanism is the foundation and key to establishing a harmonious doctor-patient relationship and improving medical quality. Although traditional encryption methods can provide certain information security protection, they cannot balance data protection and data analysis and processing and are not suitable for intelligent medical environments that require more precise medical decisions. Therefore, we propose a hierarchical identity-based inner product functional encryption scheme with a malicious user revocation mechanism aimed at addressing the privacy and security issues of patients in smart healthcare. This solution allows specific access and analysis of data while ensuring that patients’ sensitive information is protected from infringement, enabling doctors to diagnose and treat more accurately and optimize the allocation of medical resources to the greatest extent possible. Furthermore, we have formally demonstrated the security of the scheme and conducted a security analysis and performance comparison. The results show that our solution has better performance while ensuring security and is suitable for the efficient and secure data processing requirements of smart healthcare.

With the development of cloud computing, more and more data is stored in cloud servers, which leads to an increasing degree of privacy of data stored in cloud servers. For example, in the critical domain of medical vaccine trials, where public health outcomes hinge on the analysis of sensitive patient data, the imperative to safeguard privacy has never been more pronounced. Traditional encryption methods, though effective at protecting data, often expose vulnerabilities during decryption and lack the ability to support granular data access and computation. One-way re-encryption schemes further impede the agility of data sharing, which is indispensable for the collaborative efforts of research institutions. To address these limitations, we propose a novel bidirectional re-encryption scheme for inner-product functional encryption (IPFE). Our scheme secures data while allowing computation and sharing in an encrypted state, preserving patient privacy without hindering research. By harnessing inner-product functional encryption, our approach allows authorized researchers to extract valuable insights from encrypted data, significantly enhancing privacy protections. Our scheme’s security is predicated on the$l$-ABDHE (augmented bilinear Diffie-Hellman exponent) assumption, ensuring robustness against chosen plaintext attacks within the standard model. This foundation not only secures the data but also yields compact ciphertext length, minimizing storage demands. We introduce a protocol specifically designed for medical vaccine trials, which leverages our bidirectional IB-IPFRE (Identity-Based Inner-Product Functional Re-Encryption) scheme. This protocol enhances data security, supports collaborative research, and maintains patient privacy. Its application in vaccine trials demonstrates the scheme’s effectiveness in protecting sensitive information while enabling critical research insights.

As Vehicular Ad hoc Networks (VANETs) become integrated into daily life, drivers can conveniently transmit messages to other vehicles. However, since most messages are sent over public channels, they are vulnerable to leakage and tampering, posing risks to user privacy and security. A secure authentication scheme is essential to ensure message authenticity and integrity. Vehicles frequently cross multiple domains while driving, but existing schemes mainly support authentication within a single domain, making it difficult for vehicles from different domains to establish trusted connections. Moreover, many current approaches rely heavily on bilinear pairings, reducing efficiency and increasing communication overhead. To address these issues, we propose an efficient cross-domain authentication scheme for VANETs. Our scheme uses pseudonyms to protect vehicle privacy and allows vehicles to directly authenticate with entities from other domains without relying on a trusted authority, enabling the establishment of a secure session key. We verified the security of our protocol using ProVerif and evaluated its performance with JPBC, a Java-based cryptographic library. Results show that our approach outperforms existing methods and is well-suited for high-traffic, densely populated, and resource-constrained VANET environments.

With the advancement of the Internet of Things (IOT), Vehicular Ad Hoc networks (VANETs) are integrated into intelligent transportation systems to facilitate vehicle communication. However, as the number of vehicles and application diversity increase, significant security concerns have emerged, including message authentication and vehicle privacy protection. Consequently, researchers have devised several identity authentication protocols to ensure legitimate communication between parties. Nevertheless, existing schemes fail to address real-time response identity authentication due to high-speed vehicle movement and the need for traversing multiple domains. This limitation poses challenges in traffic management and even threatens human life. To overcome these issues, we propose a novel identity authentication method called broadcast authentication and design a new protocol incorporating this approach. The confidentiality and unforgeability of our proposal are proven based on classic hardness assumptions. Our protocol enables vehicles to authenticate with multiple roadside units through a single request communication process, thereby avoiding delays in authentication while saving costs associated with communication and computation. Compared with existing schemes, our protocol demonstrates superior computing efficiency and performance.

With the rapid development of Internet of Things (IoT) technology and the growth of traffic demand, vehicular ad hoc networks (VANETs) will become a major component of intelligent transportation systems. However, identity authentication in VANETs has emerged as a crucial challenge in maintaining communication security. The existing identity authentication methods have complex certificate management and key escrow problems, and many authentication schemes can not resist common attacks and are inefficient. Also, the above proposals cannot meet the lightweight needs of the IoT. At the same time, vehicles in the VANETs may move between different network domains, which will lead to an increase in cross-domain identity authentication requirements. Therefore, this article proposes an efficient and lightweight cross-domain direct identity authentication protocol. We apply the unpaired certificateless signature scheme to the cross-domain authentication and generate cross-domain communication credentials for the vehicles in advance in the local domain, which will greatly improve the efficiency of cross-domain authentication between the vehicles. In addition, we demonstrate the security of our protocol and further validate the security of the protocol through the simulation experiments. Finally, experiments show that our protocol is more efficient than the existing authentication protocols.