Presentation 2016-09-02
[Invited Talk] Adaptively Secure Identity-Based Encryption Scheme from Lattices with Asymptotically Shorter Public Parameters
Shota Yamada,
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Abstract(in Japanese) (See Japanese page)
Abstract(in English) In this paper, we present two new adaptively secure identity-based encryption schemes from lattices. The size of the public parameters, ciphertexts, and private keys are $tilde{O}(n^2 kappa^{1/d})$, $tilde{O}(n)$, and $tilde{O}(n)$ respectively. Here, $n$ is the security parameter, $kappa$ is the length of the identity, and $din mathbb{N}$ is a flexible constant number that can be set arbitrary. Ignoring the poly-logarithmic factors hidden in the asymptotic notation, our schemesachieve the best efficiency among existing adaptively secure IBE schemes from lattices. In more detail, our first scheme is anonymous, but proven secure under the LWE assumption with approximation factor $n^{omega(1)}$. Our second scheme is not anonymous, but proven adaptively secure assuming the LWE assumption for all polynomial approximation factors. Furthermore, based on a similar idea, we show an attribute-based encryption for branching programs that simultaneously satisfy the following properties for the first time: The construction achieves compact secret keys, the security is proven from the LWE assumption with polynomial approximation factor, and the scheme can deal with unbounded length branching programs.
Keyword(in Japanese) (See Japanese page)
Keyword(in English) identity-based encryption / adaptive security / lattices / short public parameters
Paper # ISEC2016-48
Date of Issue 2016-08-26 (ISEC)

Conference Information
Committee ISEC
Conference Date 2016/9/2(1days)
Place (in Japanese) (See Japanese page)
Place (in English) Kikai-Shinko-Kaikan Bldg.
Topics (in Japanese) (See Japanese page)
Topics (in English)
Chair Masahiro Mambo(Kanazawa Univ.)
Vice Chair Kazuto Ogawa(NHK) / Atsushi Fujioka(Kanagawa Univ.)
Secretary Kazuto Ogawa(Toshiba) / Atsushi Fujioka(Tohoku Univ.)
Assistant Toshihiro Ohigashi(Tokai Univ.) / Yuuji Suga(IIJ) / Atsuo Inomata(Tokyo Denki Univ.)

Paper Information
Registration To Technical Committee on Information Security
Language JPN
Title (in Japanese) (See Japanese page)
Sub Title (in Japanese) (See Japanese page)
Title (in English) [Invited Talk] Adaptively Secure Identity-Based Encryption Scheme from Lattices with Asymptotically Shorter Public Parameters
Sub Title (in English)
Keyword(1) identity-based encryption
Keyword(2) adaptive security
Keyword(3) lattices
Keyword(4) short public parameters
1st Author's Name Shota Yamada
1st Author's Affiliation National Institute of Advanced Industrial Science and Technology(AIST)
Date 2016-09-02
Paper # ISEC2016-48
Volume (vol) vol.116
Number (no) ISEC-207
Page pp.pp.59-59(ISEC),
#Pages 1
Date of Issue 2016-08-26 (ISEC)