Group Signature with Deniability: How to Disavow a Signature

Ai ISHIDA; Keita EMURA; Goichiro HANAOKA; Yusuke SAKAI; Keisuke TANAKA

doi:10.1587/transfun.E100.A.1825

Group Signature with Deniability: How to Disavow a Signature

Ai ISHIDA, Keita EMURA, Goichiro HANAOKA, Yusuke SAKAI, Keisuke TANAKA

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Group signatures are a class of digital signatures with enhanced privacy. By using this type of signature, a user can sign a message on behalf of a specific group without revealing his identity, but in the case of a dispute, an authority can expose the identity of the signer. However, it is not always the case that we need to know the specific identity of a signature. In this paper, we propose the notion of deniable group signatures, where the authority can issue a proof showing that the specified user is NOT the signer of a signature, without revealing the actual signer. We point out that existing efficient non-interactive zero-knowledge proof systems cannot be straightforwardly applied to prove such a statement. We circumvent this problem by giving a fairly practical construction through extending the Groth group signature scheme (ASIACRYPT 2007). In particular, a denial proof in our scheme consists of 96 group elements, which is about twice the size of a signature in the Groth scheme. The proposed scheme is provably secure under the same assumptions as those of the Groth scheme.

Publication: IEICE TRANSACTIONS on Fundamentals Vol.E100-A No.9 pp.1825-1837

Publication Date: 2017/09/01

Publicized

Online ISSN: 1745-1337

DOI: 10.1587/transfun.E100.A.1825

Type of Manuscript: Special Section PAPER (Special Section on Discrete Mathematics and Its Applications)

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Authors

Ai ISHIDA
  Tokyo Institute of Technology,the National Institute of Advanced Industrial Science and Technology
Keita EMURA
  the National Institute of Information and Communications Technology
Goichiro HANAOKA
  the National Institute of Advanced Industrial Science and Technology
Yusuke SAKAI
  the National Institute of Advanced Industrial Science and Technology
Keisuke TANAKA
  Tokyo Institute of Technology

Keyword

group signature, deniability, non-interactive zero-knowledge proof, bilinear map

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Ai ISHIDA, Keita EMURA, Goichiro HANAOKA, Yusuke SAKAI, Keisuke TANAKA, "Group Signature with Deniability: How to Disavow a Signature" in IEICE TRANSACTIONS on Fundamentals, vol. E100-A, no. 9, pp. 1825-1837, September 2017, doi: 10.1587/transfun.E100.A.1825.
Abstract: Group signatures are a class of digital signatures with enhanced privacy. By using this type of signature, a user can sign a message on behalf of a specific group without revealing his identity, but in the case of a dispute, an authority can expose the identity of the signer. However, it is not always the case that we need to know the specific identity of a signature. In this paper, we propose the notion of deniable group signatures, where the authority can issue a proof showing that the specified user is NOT the signer of a signature, without revealing the actual signer. We point out that existing efficient non-interactive zero-knowledge proof systems cannot be straightforwardly applied to prove such a statement. We circumvent this problem by giving a fairly practical construction through extending the Groth group signature scheme (ASIACRYPT 2007). In particular, a denial proof in our scheme consists of 96 group elements, which is about twice the size of a signature in the Groth scheme. The proposed scheme is provably secure under the same assumptions as those of the Groth scheme.
URL: https://global.ieice.org/en_transactions/fundamentals/10.1587/transfun.E100.A.1825/_p

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@ARTICLE{e100-a_9_1825,
author={Ai ISHIDA, Keita EMURA, Goichiro HANAOKA, Yusuke SAKAI, Keisuke TANAKA, },
journal={IEICE TRANSACTIONS on Fundamentals},
title={Group Signature with Deniability: How to Disavow a Signature},
year={2017},
volume={E100-A},
number={9},
pages={1825-1837},
abstract={Group signatures are a class of digital signatures with enhanced privacy. By using this type of signature, a user can sign a message on behalf of a specific group without revealing his identity, but in the case of a dispute, an authority can expose the identity of the signer. However, it is not always the case that we need to know the specific identity of a signature. In this paper, we propose the notion of deniable group signatures, where the authority can issue a proof showing that the specified user is NOT the signer of a signature, without revealing the actual signer. We point out that existing efficient non-interactive zero-knowledge proof systems cannot be straightforwardly applied to prove such a statement. We circumvent this problem by giving a fairly practical construction through extending the Groth group signature scheme (ASIACRYPT 2007). In particular, a denial proof in our scheme consists of 96 group elements, which is about twice the size of a signature in the Groth scheme. The proposed scheme is provably secure under the same assumptions as those of the Groth scheme.},
keywords={},
doi={10.1587/transfun.E100.A.1825},
ISSN={1745-1337},
month={September},}

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TY - JOUR
TI - Group Signature with Deniability: How to Disavow a Signature
T2 - IEICE TRANSACTIONS on Fundamentals
SP - 1825
EP - 1837
AU - Ai ISHIDA
AU - Keita EMURA
AU - Goichiro HANAOKA
AU - Yusuke SAKAI
AU - Keisuke TANAKA
PY - 2017
DO - 10.1587/transfun.E100.A.1825
JO - IEICE TRANSACTIONS on Fundamentals
SN - 1745-1337
VL - E100-A
IS - 9
JA - IEICE TRANSACTIONS on Fundamentals
Y1 - September 2017
AB - Group signatures are a class of digital signatures with enhanced privacy. By using this type of signature, a user can sign a message on behalf of a specific group without revealing his identity, but in the case of a dispute, an authority can expose the identity of the signer. However, it is not always the case that we need to know the specific identity of a signature. In this paper, we propose the notion of deniable group signatures, where the authority can issue a proof showing that the specified user is NOT the signer of a signature, without revealing the actual signer. We point out that existing efficient non-interactive zero-knowledge proof systems cannot be straightforwardly applied to prove such a statement. We circumvent this problem by giving a fairly practical construction through extending the Groth group signature scheme (ASIACRYPT 2007). In particular, a denial proof in our scheme consists of 96 group elements, which is about twice the size of a signature in the Groth scheme. The proposed scheme is provably secure under the same assumptions as those of the Groth scheme.
ER -