Lore: An LWE-based Key Encapsulation Mechanism  with Variable Modulus and CRT Compression

Zhongxiang Zheng; Anyu Wang; Chunhuan Zhao; Guangwu Xu; Zhengtao Jiang; Sibo Feng; Zhichen Yan; Shuang Sun; Xiaoyun Wang

Paper 2025/2093

Lore: An LWE-based Key Encapsulation Mechanism with Variable Modulus and CRT Compression

Zhongxiang Zheng, School of Computer and Cyber Sciences, Communication University of China, Beijing, China

Anyu Wang, Institute for Advanced Study, BNRist, Tsinghua University, Beijing, China

Chunhuan Zhao, Huawei Technologies, Beijing, China

Guangwu Xu, School of Cyber Science and Technology, Shandong University, QingDao, China

Zhengtao Jiang, School of Computer and Cyber Sciences, Communication University of China, Beijing, China

Sibo Feng, School of Computer and Cyber Sciences, Communication University of China, Beijing, China

Zhichen Yan, School of Computer and Cyber Sciences, Communication University of China, Beijing, China

Shuang Sun, Blockchain Laboratory, ChinaBond Finance and Information Technology Co., LTD, Beijing, China

Xiaoyun Wang, Institute for Advanced Study, BNRist, Tsinghua University, Beijing, China

Abstract

In this paper, we propose a new post-quantum lattice-based IND-CCA2-secure key encapsulation mechanism (KEM) named Lore. The scheme is based on a variant of MLWR problem following LPR structure with two new technologies called variable modulus and CRT compression, which provide a balance of decryption failure probability and ciphertext size. We prove its security in ROM/QROM and provide concrete parameters as well as reference implementation to show that our scheme enjoys high efficiency, compact bandwidth and proper decryption failure rate(DFR) corresponding to its security levels compared with former results.

Metadata

Available format(s): PDF
Category: Public-key cryptography
Publication info: Preprint.
Keywords: Lattice LWE PKE KEM DFR
Contact author(s): zhengzx @ cuc edu cn
xiaoyunwang @ tsinghua edu cn
History: 2025-11-14: approved; 2025-11-14: received; See all versions
Short URL: https://ia.cr/2025/2093
License: CC BY-NC-SA

BibTeX

@misc{cryptoeprint:2025/2093,
      author = {Zhongxiang Zheng and Anyu Wang and Chunhuan Zhao and Guangwu Xu and Zhengtao Jiang and Sibo Feng and Zhichen Yan and Shuang Sun and Xiaoyun Wang},
      title = {Lore: An {LWE}-based Key Encapsulation Mechanism  with Variable Modulus and {CRT} Compression},
      howpublished = {Cryptology {ePrint} Archive, Paper 2025/2093},
      year = {2025},
      url = {https://eprint.iacr.org/2025/2093}
}