Abstract With the development and practical application of technologies such as Fully Homomorphic Encryption (FHE), Secure Multi-Party Computation (MPC), and Zero-Knowledge Proof (ZK), it has become crucial to research the design and analysis of symmetric cryptographic primitives with low multiplicative complexity and depth. First, by using multiplication and addition over the finite field $$\mathbb {F}_{q}$$ F q , where $$q$$ q is either a prime number $$p$$ p or $$2^{n}$$ 2 n , we proposed a non-linear function over $$\mathbb {F}_{q}^{4}$$ F q 4 based on the generalized Feistel structure. This function features a multiplicative complexity of 4, a multiplicative depth of 2 and 8 additions, and its maximum differential/linear probability of the function is bounded by $$q^{-2}$$ q - 2 . Then, we designed a family of HE-friendly block ciphers called DuX. We conduct a comprehensive security analysis of DuX within certain parameters against various cryptanalysis methods, including differential cryptanalysis, linear cryptanalysis, impossible differential cryptanalysis, zero-correlation linear cryptanalysis, integral analysis, related-key differential cryptanalysis, algebraic attacks, slide attacks, reflection attacks, and boomerang attacks. Our research indicates that DuX maintains a robust security margin against those attacks. Finally, based on the BGV scheme in HElib, we present a detailed homomorphic decryption implementation of the DuX instantiated with $$q = 2^{8}$$ q = 2 8 , $$2^{16}$$ 2 16 and $$65537$$ 65537 , respectively. The results show that, for the same block size, the throughput of the DuX-128 over $$\mathbb {F}_{2^{8}}^{16}$$ F 2 8 16 can reach approximately 14.95 times, 7.85 times and 20.76 times that of the AES-128, Low MC-128 and CHAGHRI, respectively. Compared with YuX-128, its throughput has increased approximately by 21.59%.

Rong Cheng, Jinyi Liu, Yan Zheng, Fei Ni, Jiazhen Du, Hangyu Mao, Fuzheng Zhang, Bo Wang, Jianye Hao. Proceedings of the 63rd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers). 2025.

The aim of this article is to propose a novel rational feedforward tuning method, by directly mapping the feedforward signal learned by dual-loop iterative learning control (DILC) onto the corresponding reference, that achieves high performance for varying trajectory tracking tasks. The DILC algorithm is first developed by paralleling the standard iterative learning control (ILC) with an additional iterative loop. Different from the standard ILC, DILC can learn an ideal feedforward signal eliminating the reference-induced error even though a robustness filter presents for the robust convergence against model uncertainties. Then, based on the reference and the feedforward signal learned by DILC, an instrumental variable-based algorithm is developed for the parameter tuning of the rational feedforward controller, which leads to unbiased estimates and optimal accuracy in terms of variance. The proposed method combines the performance of DILC with the flexibility of rational feedforward controllers. Comparative simulation and application to an ultraprecision wafer stage illustrate the enhanced performance of the proposed approach compared to the preexisting results.

Recently, more and more data have been stored in the cloud with keyword indices so that the data users can make search over the databases. In some of these database applications, the query frequency analysis of keywords is quite important to the optimization of the databases and it is easy to be implemented when the data are not encrypted. However, with the growing demands of data privacy, it is desired that the data should be encrypted before uploaded to the cloud. Searchable encryption has been proposed which enables users to make keyword search over the encrypted data with keyword privacy. In a secure searchable encryption scheme, it is required that the keyword in each query should not be revealed. So it becomes challenging to analyze the query frequency of keywords in an encrypted database which has the pressing need of optimization. In this paper, we first consider this problem and present an efficient solution to it which enables the query frequency analysis of keywords without destroying the privacy of the encrypted data and the identity privacy of data users. We also simulate our solution and show that it is practical to the real applications.

Searchable symmetric encryption (SSE) allows a client to encrypt his data in such a manner that the data can be efficiently searched. SSE has practical application in cloud storage, where a client outsources his encrypted data to a cloud server while maintaining the searchable ability over his data. Most of the current SSE schemes assume that the cloud server is honest-but-curious. However, the cloud may actively cheat on the search process to keep its cost low. In this paper, we focus on the malicious cloud model and propose a new verifiable searchable symmetric encryption scheme. Our scheme is built on the secure indistinguishability obfuscation (iO) and can be considered as the first step to apply iO in the SSE field. Moreover, our scheme can be easily extended to multiple functionalities, such as conjunctive and boolean queries. Furthermore, it can be extended to realize a publicly verifiable SSE. Thorough analysis shows that our scheme is secure and achieves a better performance.

Summary With the rapid development of cloud computing, more and more data are being centralized into cloud server for sharing. It is a challenge problem on how to keep them both private and accessible. Re‐encryption function is a useful tool to fulfill secure cloud computing. Cloud data owners store their encrypted data on the cloud server. When other cloud users want to share the cloud data, cloud server can re‐encrypt the encrypted data for them. So data on the cloud server can be both accessible and private. Secure obfuscation for re‐encryption function can hide all the private information in the re‐encryption function, so the obfuscated program can be directly outsourced to cloud server without leaking anything about the computation task. In this paper, we study on secure obfuscation for three kinds of new re‐encryption functions: multi‐use re‐encryption, conditional re‐encryption with keyword search, and broadcast re‐encryption. We utilize the obfuscated results as tools to fulfill secure cloud computing. Cloud‐computing schemes based on obfuscation have better security compared with other tools. Copyright © 2014 John Wiley & Sons, Ltd.

Abstract Program obfuscation is a compiler that transfers a program into an unintelligible form while preserving the original functionality. Secure obfuscation for several particular function families has been raised out despite the general impossibility result presented by Barak et al. Re‐encryption function is a useful primitive, which transforms ciphertexts for one party into ciphertexts under another party's public key. Hohenberger et al. constructed a special re‐encryption function and securely obfuscated it in TCC'07, and the security is based on classical hardness assumption. In this paper, we construct a new re‐encryption function and securely obfuscate it based on the standard learning with error (LWE) assumption. LWE is proved to be reducible to standard lattice problems, which are conjectured immune to quantum cryptanalysis or ‘post‐quantum’. Besides, we discuss about the relations between these two cryptographic primitives in detail: proxy re‐encryption and obfuscation for re‐encryption functions. Copyright © 2014 John Wiley & Sons, Ltd.