Hierarchical identity-based encryption (HIBE) is an extension of identity-based encryption (IBE) where an identity of a user is organized as a hierarchical structure and a user can delegate the private key generation to another user. Providing a revocation mechanism for HIBE is highly necessary to keep a system securely. Revocable HIBE (RHIBE) is an HIBE scheme that can revoke a user’s private key if his credential is expired or revealed. In this paper, we first propose an unbounded HIBE scheme where the maximum hierarchy depth is not limited and prove its selective security under a q-type assumption. Next, we propose an efficient unbounded RHIBE scheme by combining our unbounded HIBE scheme and a binary tree structure, and then we prove its selective security. By presenting the unbounded RHIBE scheme, we solve the open problem of Seo and Emura in CT-RSA 2015.
|Title of host publication||Information Security Applications - 16th International Workshop, WISA 2015, Revised Selected Papers|
|Editors||Dooho Choi, Ho-Won Kim|
|Number of pages||12|
|Publication status||Published - 2016|
|Event||16th International Workshop on Information Security Applications, WISA 2015 - Jeju Island, Korea, Republic of|
Duration: 2015 Aug 20 → 2015 Aug 22
|Name||Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)|
|Other||16th International Workshop on Information Security Applications, WISA 2015|
|Country/Territory||Korea, Republic of|
|Period||15/8/20 → 15/8/22|
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MEST) (No. 2010-0029121). The first two authors (Geumsook Ryu and Kwangsu Lee) equally contributed to this work.
© Springer International Publishing Switzerland 2016.
- Bilinear maps
- Hierarchical identity-based encryption
- Identity-based encryption
- Unbounded hierarchy depth
ASJC Scopus subject areas
- Theoretical Computer Science
- Computer Science(all)