Paper Info
Title
Tightly-Secure Key-Encapsulation Mechanism in the Quantum Random Oracle Model.
Abstract
Key-encapsulation mechanisms secure against chosen cipher-text attacks (IND-CCA-secure KEMs) in the quantum random oracle model have been proposed by Boneh, Dagdelen, Fischlin, Lehmann, Schafner, and Zhandry (CRYPTO 2012), Targhi and Unruh (TCC 2016-B), and Hofheinz, Hovelmanns, and Kiltz (TCC 2017). However, all are non-tight and, in particular, security levels of the schemes obtained by these constructions are less than half of original security levels of their building blocks. In this paper, we give a conversion that tightly converts a weakly secure public-key encryption scheme into an IND-CCA-secure KEM in the quantum random oracle model. More precisely, we define a new security notion for deterministic public key encryption (DPKE) called the disjoint simulatability, and we propose a way to convert a disjoint simulatable DPKE scheme into an IND-CCA-secure key-encapsulation mechanism scheme without incurring a significant security degradation. In addition, we give DPKE schemes whose disjoint simulatability is tightly reduced to post-quantum assumptions. As a result, we obtain IND-CCA-secure KEMs tightly reduced to various post-quantum assumptions in the quantum random oracle model.
Year
DOI
Venue
2018
10.1007/978-3-319-78372-7_17
ADVANCES IN CRYPTOLOGY - EUROCRYPT 2018, PT III
Keywords
DocType
Volume
Tight security,Chosen-ciphertext security,Post-quantum cryptography,KEM
Conference
10822
ISSN
Citations 
PageRank 
0302-9743
5
0.40
References 
Authors
29
3
Name
Order
Citations
PageRank
Tsunekazu Saito150.40
Keita Xagawa225820.51
Takashi Yamakawa3129.35