Cryptology ePrint Archive: Report 2018/817

Understanding and Constructing AKE via Double-key Key Encapsulation Mechanism

Haiyang Xue and Xianhui Lu and Bao Li and Bei Liang and Jingnan He

Abstract: 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.

Category / Keywords: public-key cryptography / Authenticated Key Exchange, CK Model, Key Encapsulation Mechanism

Original Publication (with minor differences): IACR-ASIACRYPT-2018

Date: received 3 Sep 2018, last revised 29 Nov 2018

Contact author: haiyangxc at gmail com

Available format(s): PDF | BibTeX Citation

Note: Fix some typos

Version: 20181129:083825 (All versions of this report)

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