Paper 2017/901

Stateful Multi-Client Verifiable Computation

Christian Cachin, Esha Ghosh, Dimitrios Papadopoulos, and Björn Tackmann

Abstract

This paper develops a cryptographic protocol for outsourcing arbitrary stateful computation among multiple clients to an untrusted server, while guaranteeing integrity of the data. The clients communicate only with the server and store only a short authenticator to ensure that the server does not cheat. Our contribution is two-fold. First, we extend the recent hash&prove scheme of Fiore et al. (CCS 2016) to stateful computations that support arbitrary updates by the untrusted server, in a way that can be verified by the clients. We use this scheme to generically instantiate authenticated data types. Second, we describe a protocol for multi-client verifiable computation based on an authenticated data type, and prove that it achieves a computational version of fork linearizability. This is the strongest guarantee that can be achieved in the setting where clients do not communicate directly; it ensures correctness and consistency of outputs seen by the clients individually.

Metadata
Available format(s)
PDF
Category
Cryptographic protocols
Publication info
Preprint. MINOR revision.
Keywords
Byzantine emulationverifiable computationauthenticated data types
Contact author(s)
bta @ zurich ibm com
History
2018-08-23: last of 2 revisions
2017-09-24: received
See all versions
Short URL
https://ia.cr/2017/901
License
Creative Commons Attribution
CC BY

BibTeX

@misc{cryptoeprint:2017/901,
      author = {Christian Cachin and Esha Ghosh and Dimitrios Papadopoulos and Björn Tackmann},
      title = {Stateful Multi-Client Verifiable Computation},
      howpublished = {Cryptology ePrint Archive, Paper 2017/901},
      year = {2017},
      note = {\url{https://eprint.iacr.org/2017/901}},
      url = {https://eprint.iacr.org/2017/901}
}
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