The classic Elliptic curve digital Signature Algorithm (ECDSA) uses one inversion operation in the process of signature and verification, which greatly reduces the efficiency of digital signatures. Up to now, most research schemes improve efficiency by reducing reverse operations, but they fail to attach importance to such issues as forgery signature attack. At the same time, in the blockchain, the weak randomness of ECDSA will lead to the attack of forging random numbers, which is a potential problem of digital currency transactions. In consideration of this reason, in this article, an improved provably secure elliptic curve digital signature scheme is constructed. First, the new scheme introduces double parameters in the signature process, that can effectively resist the weak randomness attack of ECDSA in Bitcoin, and can be applied to blockchain digital currency trading systems. Second, in the random oracle model, it is provably indistinguishable against Elliptic Curve Discrete Logarithm Problem (ECDLP) under the super type I and type II adversary. Third, the new scheme avoids the inverse operation in the signature and verification phase. Compared with the ECDSA, the running speed is optimized by 50.1%. Similarly, the proposed scheme has higher computational efficiency than other existing algorithms.

The progress of smart cities is closely dependent on data, that are sensed by a number of mobile devices, and provide various intelligence services for the cities. However, with the increasing importance of data, privacy threats are increasing. Malicious actors can exploit eavesdropping and data analysis to illicitly access users’ sensitive information, which may encompass location data, preferences, social behavior, and smart home data. To this end, this article proposes a new certificateless blind signature (CLBS) scheme combined with a conditional revocation function to enhance user privacy protection in the smart city environment. Concretely, the scheme relies on an anonymous authentication mechanism to protect user identity privacy and uses an anonymous revocation mechanism to resist malicious data submission. In addition, the proposed scheme addresses the key escrow problem commonly encountered in traditional cryptosystems. The security of the scheme is verified by the random oracle model, and the bilinear pairing operation is avoided in the design to improve efficiency. Performance analysis results show that the proposed scheme improves the computational efficiency by at least 20% compared with the previous schemes.

Secure healthcare information exchange (HIE) is critical to improving medical services, enabling data interoperability, and ensuring patient privacy. However, the increasing threat posed by quantum computing challenges the reliability of conventional cryptographic mechanisms. To address this, we propose a post-quantum secure healthcare data-sharing scheme that combines the Extended Merkle Signature Scheme (XMSS) and consortium blockchain technology to guarantee the integrity, authenticity, and traceability of electronic medical records (EMRs). Furthermore, the scheme incorporates autonomous artificial intelligence (AI) to assist healthcare professionals in generating accurate and intelligent diagnostic reports, enhancing clinical decision-making. We theoretically analyze the scheme's security in the random oracle model, demonstrating that it effectively resists various threats. Performance evaluation shows that the scheme is particularly suitable for HIE scenarios as it reduces about 49% in total computational overheads and 36% in blockchain storage compared to other schemes