Unbounded hierarchical identity-based encryption with efficient revocation

Geumsook Ryu, Kwangsu Lee, Seunghwan Park, Dong Hoon Lee

Research output: Chapter in Book/Report/Conference proceedingConference contribution

18 Citations (Scopus)


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.

Original languageEnglish
Title of host publicationInformation Security Applications - 16th International Workshop, WISA 2015, Revised Selected Papers
EditorsDooho Choi, Ho-Won Kim
PublisherSpringer Verlag
Number of pages12
ISBN (Print)9783319318745
Publication statusPublished - 2016
Event16th International Workshop on Information Security Applications, WISA 2015 - Jeju Island, Korea, Republic of
Duration: 2015 Aug 202015 Aug 22

Publication series

NameLecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)
ISSN (Print)0302-9743
ISSN (Electronic)1611-3349


Other16th International Workshop on Information Security Applications, WISA 2015
Country/TerritoryKorea, Republic of
CityJeju Island

Bibliographical note

Funding 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.

Publisher Copyright:
© Springer International Publishing Switzerland 2016.


  • Bilinear maps
  • Hierarchical identity-based encryption
  • Identity-based encryption
  • Revocation
  • Unbounded hierarchy depth

ASJC Scopus subject areas

  • Theoretical Computer Science
  • Computer Science(all)


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