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Constand-round secure multi-party computation enables a group of mutually distrustful parties to jointly compute a function of their inputs in a constant-round of communication. In recent years, the constant-round secure multi-party computation protocol has improved the efficiency of the online phase by completing the multiplication computation in advance of the online phase through the Beaver triples generated in the preprocessing phase. However, the preprocessing phase of these protocols is extremely overhead-intensive and there is room for improvement. In this paper, we propose an active, constant-round secure multi-party computation (MPC) protocol which can tolerate arbitrary n − 1 corruptions. At the high level, we follow the Tiny-OT protocol and the unauthenticated garbling for garbled circuits in the preprocessing phase presented by Carmit Hazay and Peter Scholl (ASIACRYPT 2017). Particularly, we first present a new optimized Tiny-OT protocol for generating Beaver (AND) triples which is more efficient than the previous protocol, and then combine the information generated by Tiny-OT to construct an unauthenticated garbled circuit. To be precise, we also reduce the number of commitments and hash function calls in the correctness check of AND triples, and avoid using additional OT operations to compute the circuit, thus further improving communication efficiency. Our new constant-round MPC protocol has a communication complexity O (| C | Bnk) per party. Moreover, we further provide solutions to the open problem of introducing the half-gate technique into multi-party distributed garbled, which will reduce half size of the garbled table per gate. [ABSTRACT FROM AUTHOR]

Rational miners in the blockchain may admit the validity of search results directly to conserve calculation overhead without executing the validation. Such phenomenon is known as the Verifier's Dilemma that the search results of the blockchain-based searchable encryption scheme would be claimed to have been verified but devoid of valid verification. Besides, the top-k query technique utilized by most existing searchable encryption schemes fails to filter the search results from the user demands during retrieval, which results in massive ineffective access lists with high complexity. Aiming at the two problems, we present a blockchain-based multi-keyword ranked searchable encryption scheme and design a fair payment protocol for multi-user scenarios. Our scheme may achieve public verifiability and user fairness by leveraging the TrueBit network, while the data owner (DO) can withdraw search privileges from the authorized data user (DU). Also, we extend the searchable encryption scheme based on inverted index to multi-DO/multi-DU scenarios, and the HashMap index is used to diminish the response time and space complexity. Moreover, the proposed scheme supports the update of index keywords and files dynamically. To enhance retrieval accuracy, we modify the information divergence algorithm in machine learning and utilize the monotonically weighted aggregation function, which improves retrieval accuracy to around 97%. Finally, Security analysis illustrates correctness and resilience against typical attacks to verify the robustness and utility of the proposed scheme. [ABSTRACT FROM AUTHOR]

Dry skin is a common skin problem in older persons. Aim of this study was to determine the prevalence, associated factors of dry skin in older inpatients. A multicenter cross-sectional study was designed and conducted. On 31 March and 29 May in 2021 two days, fifty hospitals and two nursing homes in China participated in the study. In total, 33,769 participants were included. The mean age was 73.2 (SD 8.9) years. A whole-body skin examination and associated data collection were performed by 1067 trained nurses based on a standardized data form and methods. Descriptive and univariable analyses and multivariable logistic regressions were conducted. In total, 11,602 participants had dry skin with a prevalence of 34.4%, mainly located on the upper and lower limbs with very severe skin dryness, 21.2% of the participants reported that their dry skin had pruritus, and 12.5% complained that sleep was affected by dry skin. The stronger predictor for dry skin was nursing homes (OR 5.07, 95% CI 3.99–6.45). Other predictors for dry skin were age, male sex, nutrition, lower activity level, skincare dependence, renal and pulmonary impairment, diabetes mellitus, varicose veins, cardiovascular diseases and Parkinsonism, diuretics, statins and antibiotics. The predictive model of area under ROC curve was 0.628(95% CI 0.622–0.634). The prevalence of dry skin among Chinese older patients was at high level and was associated with multiple factors. Persons with skin dryness have a higher proportion of skin itching and poor sleep. It has been registered in the Chinese Clinical Trial Registry (ChiCTR2100042893). [ABSTRACT FROM AUTHOR]