Paper 2017/794

Anonymous Single-Round Server-Aided Verification

Elena Pagnin, Aikaterini Mitrokotsa, and Keisuke Tanaka

Abstract

Server-Aided Verification (SAV) is a method that can be employed to speed up the process of verifying signatures by letting the verifier outsource part of its computation load to a third party. Achieving fast and reliable verification under the presence of an untrusted server is an attractive goal in cloud computing and internet of things scenarios. In this paper, we describe a simple framework for SAV where the interaction between a verifier and an untrusted server happens via a single-round protocol. We propose a security model for SAV that refines existing ones and includes the new notions of SAV-anonymity and extended unforgeability. In addition, we apply our definitional framework to provide the first generic transformation from any signature scheme to a single-round SAV scheme that incorporates verifiable computation. Our compiler identifies two independent ways to achieve SAV-anonymity: computationally, through the privacy of the verifiable computation scheme, or unconditionally, through the adaptibility of the signature scheme. Finally, we define three novel instantiations of SAV schemes obtained through our compiler. Compared to previous works, our proposals are the only ones which simultaneously achieve existential unforgeability and soundness against collusion.

Metadata
Available format(s)
PDF
Category
Public-key cryptography
Publication info
Published elsewhere. Major revision. Latincrypt 2017
Keywords
Server-Aided VerificationDigital SignaturesAnonymityVerifiable Computation
Contact author(s)
elenap @ chalmers se
History
2017-08-25: received
Short URL
https://ia.cr/2017/794
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2017/794,
      author = {Elena Pagnin and Aikaterini Mitrokotsa and Keisuke Tanaka},
      title = {Anonymous Single-Round Server-Aided Verification},
      howpublished = {Cryptology ePrint Archive, Paper 2017/794},
      year = {2017},
      note = {\url{https://eprint.iacr.org/2017/794}},
      url = {https://eprint.iacr.org/2017/794}
}
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