Paper 2015/827 Original: eprint.iacr.org/2015/827 ↗

Unbounded Hierarchical Identity-Based Encryption with Efficient Revocation

Geumsook Ryu
Kwangsu Lee
Seunghwan Park
Dong Hoon Lee
Abstract

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.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Preprint.
History
2015-08-26: last updated
2015-08-26: published
Short URL
https://ia.cr/2015/827
License
https://creativecommons.org/licenses/by/4.0/

BibTeX

@misc{cryptoeprint:2015/827,
      author = {Geumsook Ryu and Kwangsu Lee and Seunghwan Park and Dong Hoon Lee},
      title = {Unbounded Hierarchical Identity-Based Encryption with Efficient Revocation},
      howpublished = {Cryptology {ePrint} Archive, Paper 2015/827},
      year = {2015},
      url = {https://eprint.iacr.org/2015/827}
}
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