Cryptology ePrint Archive: Report 2008/047

Fair Traceable Multi-Group Signatures

Vicente Benjumea and Seung Geol Choi and Javier Lopez and Moti Yung

Abstract: This paper presents fair traceable multi-group signatures (FTMGS), which have enhanced capabilities, compared to group and traceable signatures, that are important in real world scenarios combining accountability and anonymity. The main goal of the primitive is to allow multiple groups that are managed separately (managers are not even aware of the other ones), yet allowing users (in the spirit of the Identity 2.0 initiative) to manage what they reveal about their identity with respect to these groups by themselves. This new primitive incorporates the following additional features.

- While considering multiple groups it discourages users from sharing their private membership keys through two orthogonal and complementary approaches. In fact, it merges functionality similar to credential systems with anonymous type of signing with revocation.

- The group manager now mainly manages joining procedures, and new entities (called fairness authorities and consisting of various representatives, possibly) are involved in opening and revealing procedures. In many systems scenario assuring fairness in anonymity revocation is required.

We specify the notion and implement it in the random oracle model.

Category / Keywords: cryptographic protocols / digital signatures, group signatures, traceable signatures

Publication Info: Financial Cryptography 2008 (extended version of)

Date: received 29 Jan 2008, last revised 29 Jan 2008

Contact author: sgchoi at cs columbia edu

Available format(s): Postscript (PS) | Compressed Postscript (PS.GZ) | PDF | BibTeX Citation

Version: 20080130:161134 (All versions of this report)

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