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Journal of Information Science and Engineering, Vol. 26 No. 4, pp. 1243-1259 (July 2010)

Identity-based Hierarchical Designated Decryption*

SHU-HUI CHANG1, CHUAN-MING LI2 AND TZONELIH HWANG3
1Center of General Education
Southern Taiwan University of Technology
Tainan, 710 Taiwan
2Department of Information Management
Shu-Zen College of Medicine and Management
Kaohsiung, 821 Taiwan
3Department of Computer Science and Information Engineering
National Cheng Kung University
Tainan, 701 Taiwan

This paper presents an identity-based hierarchical designated decryption (IHDD) scheme which allows a message sender to generate ciphertexts that can be decrypted by (1) only a specified recipient or (2) a specified recipient and all or some of its ancestor users in the hierarchy tree. The newly proposed scheme can be considered as a combination of the hierarchical identity-based encryption (HIBE) and the identity-based multi-recipient encryption scheme (ID-based MRES). However, the purpose and structure of the proposed IHDD scheme are different from those of the HIBE and the ID-based MRES. The proposed IHDD scheme has low computation complexity, in which the decryption operation needs only one bilinear pairing computation, and constant length private keys wherein the length of users private keys is independent of the hierarchy depth. The security of the proposed scheme is based on the decision bilinear Diffie-Hellman inversion assumption without using random oracles.

Keywords: data security, hierarchical, identity-based encryption, key escrow, multi-recipient encryption

Full Text () Retrieve PDF document (201007_06.pdf)

Received June 20, 2008; revised December 2, 2008 & March 9, 2009; accepted August 13, 2009.
Communicated by Wen-Guey Tzeng.
* This research was supported by the National Science Council of Taiwan, R.O.C., under the Contract No. NSC 95-2221-E-006-071.