Understanding and constructing AKE via double-key key encapsulation mechanism

• Main Authors: XUE, Haiyang, LU, Xianhui, LI, Bao, LIANG, Bei, HE, Jingnan
• Format: text
• Language: English
• Published: Institutional Knowledge at Singapore Management University 2018
• Subjects: Authenticated key exchange; CK model Key encapsulation mechanism; Information Security
• Online Access: https://ink.library.smu.edu.sg/sis_research/9206; https://ink.library.smu.edu.sg/context/sis_research/article/10211/viewcontent/understanding_and_constructing.pdf
• Institution: Singapore Management University

Motivated by abstracting the common idea behind several implicitly authenticated key exchange (AKE) protocols, we introduce a primitive that we call double-key key encapsulation mechanism (2-key KEM). It is a special type of KEM involving two pairs of secret-public keys and satisfying some function and security property. Such 2-key KEM serves as the core building block and provides alternative approaches to simplify the constructions of AKE. To see the usefulness of 2-key KEM, we show how several existing constructions of AKE can be captured as 2-key KEM and understood in a unified framework, including widely used HMQV, NAXOS, Okamoto-AKE, and FSXY12-13 schemes. Then, we show (1) how to construct 2-key KEM from concrete assumptions, (2) how to adapt the classical Fujisaki-Okamoto transformation and KEM combiner to achieve the security requirement of 2-key KEM, (3) an elegant Kyber-AKE over lattice using the improved Fujisaki-Okamoto technique.