IEICE Transactions on Communications
Online ISSN : 1745-1345
Print ISSN : 0916-8516
Regular Section
Hierarchical CRGK Supporting a Secure Multicast Communication for a Large Number of Users
Jihyun PARKJeongsu LEEJeonghyun KIMJaecheol RYOU
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2010 Volume E93.B Issue 4 Pages 862-870


A multicast content service, including numerous devices, requires an efficient group key management scheme as one of its core components. The purpose of group key management is to provide a secure key-sharing scheme among the members of a group so that messages transmitted via broadcasting or multicasting are not exposed to non-members. The Chinese Remaindering Group Key (CRGK) is an efficient group key management scheme based on the Chinese Remainder Theorem (CRT). It optimizes the number of re-key messages, the user-side key computation cost, and the number of stored keys. However, CRGK is not fit for a group with a large number of members because of the high computation complexity of the CRT. In this paper, we propose a Hierarchical CRGK (HCRGK) scheme that supports a group with a large number of members. We improved CRGK by adopting it to include an n-ary tree structure. The tree approach simplifies the group key management by distributing the group key computation to subgroups. Our scheme requires at most (logmN + 1) re-key messages for a group with N members and a short computation time even when the group is very large.

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© 2010 The Institute of Electronics, Information and Communication Engineers
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