International Association for Cryptologic Research

International Association
for Cryptologic Research


Modes of Operation Suitable for Computing on Encrypted Data

Dragos Rotaru , University of Bristol
Nigel P. Smart , University of Bristol
Martijn Stam , University of Bristol
DOI: 10.13154/tosc.v2017.i3.294-324
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Abstract: We examine how two parallel modes of operation for Authenticated Encryption (namely CTR+PMAC and OTR mode) work when evaluated in a multiparty computation engine. These two modes are selected because they suit the PRFs examined in previous works. In particular the modes are highly parallel, and do not require evaluation of the inverse of the underlying PRF. In order to use these modes one needs to convert them from their original instantiation of being defined on binary blocks of data, to working on elememts in a large prime finite field. The latter fitting the use case of many secret-sharing based MPC engines. In doing this conversion we examine the associated security proofs of PMAC and OTR, and show that they carry over to this new setting.
  title={Modes of Operation Suitable for Computing on Encrypted Data},
  journal={IACR Trans. Symmetric Cryptol.},
  publisher={Ruhr-Universit├Ąt Bochum},
  volume={2017, Issue 3},
  author={Dragos Rotaru and Nigel P. Smart and Martijn Stam},