Authenticated Garbling and Communication-Efficient, Constant-Round, Secure Two-Party Computation.

We propose a simple and efficient framework for obtaining efficient constant-round protocols for maliciously secure two-party computation. Our framework uses a function-independent preprocessing phase to generate authenticated information for the two parties; this information is then used to construct a single "authenticated" garbled circuit which is transmitted and evaluated. We also show how to efficiently instantiate the preprocessing phase with a new, highly optimized version of the TinyOT protocol by Nielsen et al.We propose a simple and efficient framework for obtaining efficient constant-round protocols for maliciously secure two-party computation. Our framework uses a function-independent preprocessing phase to generate authenticated information for the two parties; this information is then used to construct a single "authenticated" garbled circuit which is transmitted and evaluated. We also show how to efficiently instantiate the preprocessing phase with a new, highly optimized version of the TinyOT protocol by Nielsen et al.

ACM SIGSAC Conference on Computer and Communications Security (CCS)Oct 27, 2017173 citations

Two-Round Concurrently Secure Two-Party Computation.

Behzad Abdolmaleki, Giulio Malavolta, Ahmadreza Rahimi

Jan 1, 20210 citations

Maliciously Secure MPC From Semi-Honest 2PC in the Server-Aided Model

Yibiao Lu, Bingsheng Zhang, Kui Ren

Secure multi-party computation (MPC) provides provable security guarantees for many privacy critical applications. The semi-honest MPC protocols are secure against semi-honest adversaries who can only observe the protocol execution, while the maliciously secure MPC protocols are secure against malicious adversaries who can deviate from the protocol description arbitrarily. Many security sensitive applications tend to use semi-honest MPC protocols because malicious security comes with huge communication and/or computation costs. In this work, we show how to efficiently transform generic semi-honest two-party protocols into maliciously secure multi-party protocol in the server-aided setting. We further propose an optimized constant-round server-aided MPC protocol. The proposed protocols are secure when all but one parties are maliciously corrupted, while the remaining party and the server are corrupted by semi-honest and non-colluding adversaries. We implement and evaluate our constant-round protocol. For the 2-party case, our protocol is only 1.11× slower than thesemi-honestYao's Garbled Circuits protocol, and it is 9.16× faster than the maliciously secure authenticated garbling protocol and 4.96× faster than the state-of-the-art maliciously secure server-aided protocol of Wuet al.For the 8-party case, our protocol is 103.29× faster than the authenticated garbling protocol and 17.03× faster than the protocol of Wuet al.Secure multi-party computation (MPC) provides provable security guarantees for many privacy critical applications. The semi-honest MPC protocols are secure against semi-honest adversaries who can only observe the protocol execution, while the maliciously secure MPC protocols are secure against malicious adversaries who can deviate from the protocol description arbitrarily. Many security sensitive applications tend to use semi-honest MPC protocols because malicious security comes with huge communication and/or computation costs. In this work, we show how to efficiently transform generic semi-honest two-party protocols into maliciously secure multi-party protocol in the server-aided setting. We further propose an optimized constant-round server-aided MPC protocol. The proposed protocols are secure when all but one parties are maliciously corrupted, while the remaining party and the server are corrupted by semi-honest and non-colluding adversaries. We implement and evaluate our constant-round protocol. For the 2-party case, our protocol is only 1.11× slower than thesemi-honestYao's Garbled Circuits protocol, and it is 9.16× faster than the maliciously secure authenticated garbling protocol and 4.96× faster than the state-of-the-art maliciously secure server-aided protocol of Wuet al.For the 8-party case, our protocol is 103.29× faster than the authenticated garbling protocol and 17.03× faster than the protocol of Wuet al.

IEEE Transactions on Dependable and Secure ComputingOct 6, 20239 citations

More Efficient MPC from Improved Triple Generation and Authenticated Garbling

Kang Yang, Xiao Shaun Wang, Jiang Zhang

Recent works on distributed garbling have provided highly efficient solutions for constant-round MPC tolerating an arbitrary number of corruptions. In this work, we improve upon state-of-the-art protocols in this paradigm for further performance gain. First, we propose a new protocol for generating authenticated AND triples, which is a key building block in many recent works. \beginitemize \item We propose a new authenticated bit protocol in the two-party and multi-party settings from bare IKNP OT extension, allowing us to reduce the communication by about $24%$ and eliminate many computation bottlenecks. We further improve the computational efficiency for multi-party authenticated AND triples with cheaper and fewer consistency checks and fewer hash function calls. \item We implemented our triple generation protocol and observe around $4\times$ to $5\times$ improvement compared to the best prior protocol in most settings. For example, in the two-party setting with 10 Gbps network and 8 threads, our protocol can generate more than $4$ million authenticated triples per second, while the best prior implementation can only generate $0.8$ million triples per second. In the multi-party setting, our protocol can generate more than $37000$ triples per second over 80 parties, while the best prior protocol can only generate the same number of triples per second over 16 parties. \enditemize We also improve the state-of-the-art multi-party authenticated garbling protocol. \beginitemize \item We take the first step towards applying half-gates in the multi-party setting, which enables us to reduce the size of garbled tables by $2κ$ bits per gate per garbler, where κ is the computational security parameter. This optimization is also applicable in the semi-honest multi-party setting. \item We further reduce the communication of circuit authentication from $4ρ$ bits to $1$ bit per gate, using a new multi-party batched circuit authentication, where ρ is the statistical security parameter. Prior solution with similar efficiency is only applicable in the two-party setting. \enditemize For example, in the three-party setting, our techniques can lead to roughly a $35%$ reduction in the size of a distributed garbled circuit.Recent works on distributed garbling have provided highly efficient solutions for constant-round MPC tolerating an arbitrary number of corruptions. In this work, we improve upon state-of-the-art protocols in this paradigm for further performance gain. First, we propose a new protocol for generating authenticated AND triples, which is a key building block in many recent works. \beginitemize \item We propose a new authenticated bit protocol in the two-party and multi-party settings from bare IKNP OT extension, allowing us to reduce the communication by about $24%$ and eliminate many computation bottlenecks. We further improve the computational efficiency for multi-party authenticated AND triples with cheaper and fewer consistency checks and fewer hash function calls. \item We implemented our triple generation protocol and observe around $4\times$ to $5\times$ improvement compared to the best prior protocol in most settings. For example, in the two-party setting with 10 Gbps network and 8 threads, our protocol can generate more than $4$ million authenticated triples per second, while the best prior implementation can only generate $0.8$ million triples per second. In the multi-party setting, our protocol can generate more than $37000$ triples per second over 80 parties, while the best prior protocol can only generate the same number of triples per second over 16 parties. \enditemize We also improve the state-of-the-art multi-party authenticated garbling protocol. \beginitemize \item We take the first step towards applying half-gates in the multi-party setting, which enables us to reduce the size of garbled tables by $2κ$ bits per gate per garbler, where κ is the computational security parameter. This optimization is also applicable in the semi-honest multi-party setting. \item We further reduce the communication of circuit authentication from $4ρ$ bits to $1$ bit per gate, using a new multi-party batched circuit authentication, where ρ is the statistical security parameter. Prior solution with similar efficiency is only applicable in the two-party setting. \enditemize For example, in the three-party setting, our techniques can lead to roughly a $35%$ reduction in the size of a distributed garbled circuit.

ACM SIGSAC Conference on Computer and Communications Security (CCS)Oct 30, 202053 citations

24%

and eliminate many computation bottlenecks. We further improve the computational efficiency for multi-party authenticated AND triples with cheaper and fewer consistency checks and fewer hash function calls. \item We implemented our triple generation protocol and observe around

4\times

5\times

improvement compared to the best prior protocol in most settings. For example, in the two-party setting with 10 Gbps network and 8 threads, our protocol can generate more than

4

million authenticated triples per second, while the best prior implementation can only generate

0.8

million triples per second. In the multi-party setting, our protocol can generate more than

37000

triples per second over 80 parties, while the best prior protocol can only generate the same number of triples per second over 16 parties. \enditemize We also improve the state-of-the-art multi-party authenticated garbling protocol. \beginitemize \item We take the first step towards applying half-gates in the multi-party setting, which enables us to reduce the size of garbled tables by

2κ

bits per gate per garbler, where κ is the computational security parameter. This optimization is also applicable in the semi-honest multi-party setting. \item We further reduce the communication of circuit authentication from

4ρ

bits to

1

bit per gate, using a new multi-party batched circuit authentication, where ρ is the statistical security parameter. Prior solution with similar efficiency is only applicable in the two-party setting. \enditemize For example, in the three-party setting, our techniques can lead to roughly a

35%

reduction in the size of a distributed garbled circuit.