Forward-Secure Group Signatures from Pairings

Toru NAKANISHI  Yuta HIRA  Nobuo FUNABIKI  

Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E93-A    No.11    pp.2007-2016
Publication Date: 2010/11/01
Online ISSN: 1745-1337
DOI: 10.1587/transfun.E93.A.2007
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Information Theory and Its Applications)
Category: Cryptography and Information Security
Keyword: 
anonymity,  group signatures,  forward-security,  pairings,  

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Summary: 
To reduce the damage of key exposures, forward-secure group signature schemes have been first proposed by Song. In the forward-secure schemes, a secret key of a group member is updated by a one-way function every interval and the previous secret key is erased. Thus, even if a secret key is exposed, the signatures produced by the secret keys of previous intervals remain secure. Since the previous forward-secure group signature schemes are based on the strong RSA assumption, the signatures are longer than pairing-based group signatures. In addition, the complexity of the key update or signing/verification is O(T), where T is the total number of intervals. In this paper, a forward-secure group signature scheme from pairings is proposed. The complexity of our key update and signing/verification is O(log T).