关键词: 格, 密钥封装机制（KEM）, 机密性, 可认证性, 标准模型

Abstract: Key encapsulation mechanisms (KEM) make both sides of the session can safely share a random session key. It is one of the effective solutions for key distribution and key management problems in large-scale networks, which can copy with the problem of space constraints when using public key to encrypt plaintext. This paper constructs a secure and efficient key encapsulation mechanism in the standard model from lattice by combining new trapdoor function and dual-LWE (learning with errors) algorithm organically, and involves the identity information of the participant to guarantee the confidentiality and authentication. The mechanism can resist the existing known quantum algorithm attacks. At the same time, ciphertext compression technology is used to improve transmission efficiency in the analysis results. The security of the proposed mechanism is proven to chosen-ciphertext security and strictly reduced to the hardness of decisional LWE problem in the standard model. The new mechanism is suitable for various types of authenticated key exchange protocols based on lattice cryptography.

Key words: lattice, key encapsulation mechanism (KEM), confidentiality, authentication, standard model