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Security analysis of a privacy‐preserving decentralized ciphertext‐policy attribute‐based encryption scheme
Author(s) -
Wang Minqian,
Zhang Zhenfeng,
Chen Cheng
Publication year - 2015
Publication title -
concurrency and computation: practice and experience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.309
H-Index - 67
eISSN - 1532-0634
pISSN - 1532-0626
DOI - 10.1002/cpe.3623
Subject(s) - collusion , encryption , computer science , computer security , attribute based encryption , ciphertext , information privacy , identifier , semantic security , scheme (mathematics) , public key cryptography , computer network , mathematics , business , mathematical analysis , industrial organization
Summary As it does not require a central authority or the cooperation among multiple authorities, decentralized attribute‐based encryption is an efficient and flexible multi‐authority attribute‐based encryption system. In most existing multi‐authority attribute‐based encryption schemes, a global identifier (GID) is introduced to act as the linchpin to resist collusion attacks. Because GID as well as some sensitive attributes used to apply for secret keys will lead to the compromise of user's privacy, some schemes towards solving these privacy issues have been proposed. Nevertheless, only the privacy of GID was considered in prior works. Recently in ESORICS 2014, Han et al. put forward a privacy‐preserving decentralized ciphertext‐policy attribute‐based encryption scheme in the standard model to address the additive privacy of attributes. In their work, a privacy‐preserving key extract protocol is presented to protect both user's identifier and attributes. In this paper, we point out the security weakness of the scheme of Han et al. We present a collusion attack on their basic decentralized ciphertext‐policy attribute‐based encryption scheme and additionally show that the privacy protection of attributes in their privacy‐preserving key extract protocol cannot be provided. Copyright © 2015 John Wiley & Sons, Ltd.