1. SpOT-Light: Lightweight Private Set Intersection from Sparse OT Extension 2019 Crypto PSI
    Benny Pinkas and Mike Rosulek and Ni Trieu and Avishay Yanai
    [View PDF on eprint.iacr.org]
    [Show BibTex Citation]

    @misc{cryptoeprint:2019:634,
    author = {Benny Pinkas and Mike Rosulek and Ni Trieu and Avishay Yanai},
    title = {SpOT-Light: Lightweight Private Set Intersection from Sparse OT Extension},
    howpublished = {Cryptology ePrint Archive, Report 2019/634},
    year = {2019},
    note = {\url{https://eprint.iacr.org/2019/634}},
    }

We describe a novel approach for two-party private set intersection (PSI) with semi-honest security. Compared to existing PSI protocols, ours has a more favorable balance between communication and computation. Specifically, our protocol has the lowest monetary cost of any known PSI protocol, when run over the Internet using cloud-based computing services (taking into account current rates for CPU + data). On slow networks (e.g., 10Mbps) our protocol is actually the fastest.

Our novel underlying technique is a variant of oblivious transfer (OT) extension that we call sparse OT extension. Conceptually it can be thought of as a communication-efficient multipoint oblivious PRF evaluation. Our sparse OT technique relies heavily on manipulating high-degree polynomials over large finite fields (i.e. elements whose representation requires hundreds of bits). We introduce extensive algorithmic and engineering improvements for interpolation and multi-point evaluation of such polynomials, which we believe will be of independent interest.

Finally, we present an extensive empirical comparison of state-of-the- art PSI protocols in several application scenarios and along several dimensions of measurement: running time, communication, peak memory consumption, and — arguably the most relevant metric for practice — monetary cost

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