Paper 2012/605

Secure Outsourced Attribute-Based Signatures

Jin Li, Xiaofeng Chen, Jingwei Li, Chunfu Jia, Duncan S. Wong, and Willy Susilo

Abstract

Attribute-based signature (ABS) is a useful variant of digital signature, which enables users to sign messages over attributes without revealing any information other than the fact that they have attested to the messages. However, heavy computational cost is required during signing in existing work of ABS, which grows linearly with the size of the predicate formula. As a result, this presents a significant challenge for resource-limited users (such as mobile devices) to perform such heavy computation independently. Aiming at tackling the challenge above, we propose and formalize a new paradigm called OABS, in which the computational overhead at user side is greatly reduced through outsourcing such intensive computation to an untrusted signing-cloud service provider (S-CSP). Furthermore, we apply this novel paradigm to existing ABS to reduce complexity and present two schemes, i) in the first OABS scheme, the number of exponentiations involving in signing is reduced from $O(d)$ to $O(1)$ (nearly three), where $d$ is the upper bound of threshold value defined in the predicate; ii) our second scheme is built on Herranz et al's construction with constant-size signatures. The number of exponentiations in signing is reduced from $O(d^2)$ to $O(d)$ and the communication overhead is $O(1)$. Security analysis demonstrates that both OABS schemes are secure in terms of the unforgeability and attribute-signer privacy definitions specified in the proposed security model. Finally, to allow for high efficiency and flexibility, we discuss extensions of OABS and show how to achieve accountability and outsourced verification as well.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Published elsewhere. Unknown where it was published
Keywords
attribute-based signatureoutsourcecloud computing
Contact author(s)
jinli71 @ gmail com
lijw1987 @ gmail com
History
2012-10-26: received
Short URL
https://ia.cr/2012/605
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2012/605,
      author = {Jin Li and Xiaofeng Chen and Jingwei Li and Chunfu Jia and Duncan S.  Wong and Willy Susilo},
      title = {Secure Outsourced Attribute-Based Signatures},
      howpublished = {Cryptology ePrint Archive, Paper 2012/605},
      year = {2012},
      note = {\url{https://eprint.iacr.org/2012/605}},
      url = {https://eprint.iacr.org/2012/605}
}
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