Get Shorty via Group Signatures without Encryption

  • Patrik Bichsel
  • Jan Camenisch
  • Gregory Neven
  • Nigel P. Smart
  • Bogdan Warinschi
Conference paper

DOI: 10.1007/978-3-642-15317-4_24

Volume 6280 of the book series Lecture Notes in Computer Science (LNCS)
Cite this paper as:
Bichsel P., Camenisch J., Neven G., Smart N.P., Warinschi B. (2010) Get Shorty via Group Signatures without Encryption. In: Garay J.A., De Prisco R. (eds) Security and Cryptography for Networks. SCN 2010. Lecture Notes in Computer Science, vol 6280. Springer, Berlin, Heidelberg

Abstract

Group signatures allow group members to anonymously sign messages in the name of a group such that only a dedicated opening authority can reveal the exact signer behind a signature. In many of the target applications, for example in sensor networks or in vehicular communication networks, bandwidth and computation time are scarce resources and many of the existent constructions simply cannot be used. Moreover, some of the most efficient schemes only guarantee anonymity as long as no signatures are opened, rendering the opening functionality virtually useless.

In this paper, we propose a group signature scheme with the shortest known signature size and favorably comparing computation time, whilst still offering a strong and practically relevant security level that guarantees secure opening of signatures, protection against a cheating authority, and support for dynamic groups. Our construction departs from the popular sign-and-encrypt-and-prove paradigm, which we identify as one source of inefficiency. In particular, our proposal does not use standard encryption and relies on re-randomizable signature schemes that hide the signed message so as to preserve the anonymity of signers.

Security is proved in the random oracle model assuming the XDDH, LRSW and SDLP assumptions and the security of an underlying digital signature scheme. Finally, we demonstrate how our scheme yields a group signature scheme with verifier-local revocation.

Keywords

Group signatures pairings group signature security definition 

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Copyright information

© Springer-Verlag Berlin Heidelberg 2010

Authors and Affiliations

  • Patrik Bichsel
    • 1
  • Jan Camenisch
    • 1
  • Gregory Neven
    • 1
  • Nigel P. Smart
    • 2
  • Bogdan Warinschi
    • 2
  1. 1.IBM ResearchZurichSwitzerland
  2. 2.Dept Computer ScienceUniveristy of BristolUnited Kingdom