Abstract Transport Layer Cryptography Protocol (TLCP) is a secure communication protocol developed in China, featuring a dual-certificate architecture and incorporating ShangMi cryptographic algorithms. It has been widely deployed in security-critical domains such as finance, government, and energy. Despite its practical significance, TLCP did not undergo comprehensive formal analysis during its standardization process, leaving potential design-level vulnerabilities insufficiently explored. Moreover, the advent of quantum computing poses fundamental challenges to the classical cryptographic primitives employed by TLCP, motivating the need for both systematic security evaluation and post-quantum enhancements. To address these gaps, we first construct the comprehensive formal model of TLCP, covering certificate-based and identity-based cipher suites as well as its distinctive dual-certificate mechanism, under a realistic threat model and security assumptions that capture both classical and quantum adversaries. Based on this model, we conduct an automated security analysis using ProVerif, identifying nine potential attack vectors and deriving five concrete mitigation recommendations. Finally, motivated by the analysis results and the limitations of incremental fixes against quantum threats, we propose KEMTLCP, a post-quantum secure variant of TLCP that leverages key encapsulation mechanisms (KEMs) for both key exchange and authentication while preserving TLCP’s architectural principles through a novel explicit authentication mechanism. We further provide a security proof for the core authentication mechanism, show that KEMTLCP effectively mitigates the majority of identified vulnerabilities through formal analysis, and evaluate its practical performance.

There is no quantum election protocol that can fulfil the eight requirements of an electronic election protocol, i.e., completeness, robustness, privacy, legality, unreusability, fairness, verifiability, and receipt-freeness. To address this issue, we employ the general construction of quantum digital signature and quantum public key encryption, in conjunction with classic public key encryption, to develop and instantiate a general construction of quantum election protocol. The proposed protocol exhibits the following advantages: (i) no pre-shared key between any two participants is required, and no trusted third party or anonymous channels are required. The protocol is suitable for large-scale elections with numerous candidates and voters and accommodates the situation in which multiple voters vote simultaneously. (ii) It is the first protocol that dismantles the contradiction between verifiability and receipt-freeness in a quantum election protocol. It satisfies all eight requirements stated earlier under the physical assumptions that there exists a one-way untappable channel from the administrator to the voter and that there is no collusion between any of the three parties in the protocol. Compared with current election protocols with verifiability and receipt-freeness, this protocol relies upon fewer physical assumptions. (iii) This construction is flexible and can be instantiated into an election scheme having post-quantum security by applying cryptographic algorithms conveying post-quantum security. Moreover, utilizing quantum digital signature and public key encryption yields a good result: the transmitted ballots are in quantum states, so owing to the no-cloning theorem, ballot privacy is less likely to be compromised, even if private keys of the signature and public key encryption are leaked after the election. However, in existing election protocols employing classic digital signatures and public key encryption, ballot privacy can be easily violated if attackers obtain private keys. Thus, our construction enhances privacy.

In this paper we propose an active contour model for segmentation based on the Chan–Vese model. The new model can capture inherent sharp features, i.e., the sharp corners of objects, which are often smoothed by the regularization term in segmentation. Motivated by the snaked based method in [M. Droske and A. Bertozzi, SIAM J. Imaging Sci., 3 (2010), pp. 21–51] that emphasizes straight edges and corners without regard to orientation, we develop a region based method with a level set representation. The model combines the Chan–Vese model with the level set version of a higher order nonlinear term. We extend this model to multispectral images. Higher order methods can be very stiff, so we propose a splitting scheme to remove the stiffness and prove the model's stability and convergence. Finally we show numerical results on gray, color, and hyperspectral images. We can see that the model is robust to noise.

The Atmospheric Infrared Sounder (AIRS) is the first of a new generation of high spectral resolution atmospheric sounders, which are expected to obtain atmospheric temperature and water vapor profiles with high accuracy. We are interested in investigating the validation of AIRS surface air temperature retrievals, particularly in the region of China. The surface air temperature observations obtained from 540 ground meteorological stations over China were collected, and quantitative comparisons were performed between the AIRS Version 4 retrievals and the ground observations. Then, the main causes of retrieval errors are discussed in detail. Results show that the rms errors of the AIRS surface air temperature retrievals are correlated with the terrain altitudes of the meteorological stations. With the altitude increasing, the rms errors have a trend of gradual increase. The rms errors are insensitive to the ground-observed cloud fraction. With the observed cloud fraction increasing, the small-scale oscillations of rms errors occur. In mountainous and desert regions, the rms errors are larger and can reach up to 11 K sometimes. Furthermore, the AIRS surface air temperature retrievals have better performance in January than in July. In central and eastern China, even the accuracy of accepted quality products in January approaches the goal of the AIRS Team.