Linear-Complexity Private Set Intersection Protocols Secure in Malicious Model

Abstract In 2-party Circuit-based Private Set Intersection (Circuit-PSI), P 0 and P 1 hold sets S0 and S1 respectively and wish to securely compute a function f over the set S0 ∩ S1 (e.g., cardinality, sum over associated attributes, or threshold intersection). Following a long line of work, Pinkas et al. (PSTY, Eurocrypt 2019) showed how to construct a concretely efficient Circuit-PSI protocol with linear communication complexity. However, their protocol requires super-linear computation. In this work, we construct concretely efficient Circuit-PSI protocols with linear computational and communication cost. Further, our protocols are more performant than the state-of-the-art, PSTY – we are ≈ 2.3× more communication efficient and are up to 2.8× faster. We obtain our improvements through a new primitive called Relaxed Batch Oblivious Programmable Pseudorandom Functions (RB-OPPRF) that can be seen as a strict generalization of Batch OPPRFs that were used in PSTY. This primitive could be of independent interest.

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Practical Private Set Intersection Protocols with Linear Complexity

Financial Cryptography and Data Security - Lecture Notes in Computer Science ◽

10.1007/978-3-642-14577-3_13 ◽

2010 ◽

pp. 143-159 ◽

Cited By ~ 142

Author(s):

Emiliano De Cristofaro ◽

Gene Tsudik

Keyword(s):

Linear Complexity ◽

Set Intersection ◽

Private Set Intersection

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Are you The One to Share? Secret Transfer with Access Structure

Proceedings on Privacy Enhancing Technologies ◽

10.1515/popets-2017-0010 ◽

2017 ◽

Vol 2017 (1) ◽

pp. 149-169 ◽

Cited By ~ 3

Author(s):

Yongjun Zhao ◽

Sherman S.M. Chow

Keyword(s):

State Of The Art ◽

Bloom Filter ◽

Access Structure ◽

Polynomial Evaluation ◽

Threshold Policy ◽

Oblivious Polynomial Evaluation ◽

Set Intersection ◽

Malicious Model ◽

Private Set Intersection ◽

The One

Abstract Sharing information to others is common nowadays, but the question is with whom to share. To address this problem, we propose the notion of secret transfer with access structure (STAS). STAS is a twoparty computation protocol that enables the server to transfer a secret to a client who satisfies the prescribed access structure. In this paper, we focus on threshold secret transfer (TST), which is STAS for threshold policy and can be made more expressive by using linear secret sharing. TST enables a number of applications including a simple construction of oblivious transfer (OT) with threshold access control, and (a variant of) threshold private set intersection (t-PSI), which are the first of their kinds in the literature to the best of our knowledge. The underlying primitive of STAS is a variant of OT, which we call OT for a sparse array. We provide two constructions which are inspired by state-of-the-art PSI techniques including oblivious polynomial evaluation (OPE) and garbled Bloom filter (GBF). The OPEbased construction is secure in the malicious model, while the GBF-based one is more efficient. We implemented the latter one and showed its performance in applications such as privacy-preserving matchmaking.

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