A Short Verifier-Local Revocation Group Signature Scheme with Backward Unlinkability
Previously Verifier-Local Revocation (VLR) group signature schemes from bilinear maps were proposed. In VLR schemes, only verifiers are involved in the revocation of a member, while signers are not involved in the revocation. Thus, the schemes are suitable for mobile environments. Furthermore, the previously proposed schemes satisfy an important property, the backward unlinkability. It means that even after a member is revoked, signatures produced by the member before the revocation remain anonymous. This property is needed in case a member leaves voluntarily or in case of a stolen key. In this paper an improved scheme is proposed, where the group signatures are shorter. This is achieved using a different assumption, DLDH assumption, and improving zero-knowledge proofs in the group signatures. The length of the proposed group signatures is about 53% of that of the previous ones.
Keywordsgroup signature revocation backward unlinkability bilinear maps DLDH assumption
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- 5.Boneh, D., Boyen, X., Shacham, H.: Short group signatures. In: Franklin, M. (ed.) CRYPTO 2004. LNCS, vol. 3152, pp. 41–55. Springer, Heidelberg (2004)Google Scholar
- 6.Boneh, D., Shacham, H.: Group signatures with verifier-local revocation. In: Proc. ACM-CCS 2004, pp. 168–177 (2004)Google Scholar
- 8.Chaum, D., van Heijst, E.: Group signatures. In: Davies, D.W. (ed.) EUROCRYPT 1991. LNCS, vol. 547, pp. 257–265. Springer, Heidelberg (1991)Google Scholar
- 11.Miyaji, A., Nakabayashi, M., Takano, S.: New explicit conditions of elliptic curve traces for FR-reduction. IEICE Trans. Fundamentals E84-A(5), 1234–1243 (2001)Google Scholar
- 14.Song, D.X.: Practical forward secure group signature schemes. In: Proc. ACM-CCS 2001, pp. 225–234 (2001)Google Scholar
- 15.Sujing, Z., Dongdai, L.: A shorter group signature with verifier-location revocation and backward unlinkability. Cryptology ePrint Archive: Report 2006/100 (2006)Google Scholar