Adaptively Secure MPC with Sublinear Communication Complexity

Cohen, Ran; Shelat, Abhi; Wichs, Daniel

doi:10.1007/978-3-030-26951-7_2

Cited by 24 publications

(11 citation statements)

References 76 publications

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“…Their construction relies on complexity leveraging which entails a sub-exponential loss relative to IO and one-way functions. Hence, we obtain the following corollary improving on Theorem 7 in the proceedings version of [CsW19] in a black-box way.…”

Section: Invertibilitymentioning

confidence: 69%

“…Thus, we obtain the first instantiation of an adaptive explainability compiler [DKR15] without complexity leveraging and, hence, based only on polynomial hardness assumptions. The recent work of Cohen, shelat, and Wichs [CsW19] uses such an adaptive explainability compiler to obtain succinct adaptive MPC, where "succinct" means that the communication complexity is sublinear in the complexity of the evaluated function. Due to our instantiation of acPREH rand ≈c from polynomial iO, we improve the results of [CsW19] by relaxing the requirement for subexponentially secure iO to polynomially secure iO in a black-box way.…”

Section: New Results For Adaptively Secure Computationmentioning

confidence: 99%

“…-We bootstrap "adaptive PRE" from "static PRE"(Theorem 1). As a consequence, one can base succinct adaptively secure computation on standard iO as opposed to subexponential iO [CsW19](Corollary 3).…”

Section: Overview Of Contributionsmentioning

confidence: 99%

“…Particularly, Corollary 2 together with [DKR15] yields the first instantiation of an adaptive explainability compiler without complexity leveraging and, hence, based only on polynomial hardness assumptions. The recent paper [CsW19] uses such an adaptive explainability compiler to obtain adaptive MPC with communication complexity which is sub-linear in the circuit size. Their construction relies on complexity leveraging which entails a sub-exponential loss relative to IO and one-way functions.…”

Section: Invertibilitymentioning

confidence: 99%

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On Pseudorandom Encodings

Agrikola

Couteau

Ishai

et al. 2020

Theory of Cryptography

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We initiate a study of pseudorandom encodings: efficiently computable and decodable encoding functions that map messages from a given distribution to a random-looking distribution. For instance, every distribution that can be perfectly and efficiently compressed admits such a pseudorandom encoding. Pseudorandom encodings are motivated by a variety of cryptographic applications, including password-authenticated key exchange, "honey encryption" and steganography.The main question we ask is whether every efficiently samplable distribution admits a pseudorandom encoding. Under different cryptographic assumptions, we obtain positive and negative answers for different flavors of pseudorandom encodings, and relate this question to problems in other areas of cryptography. In particular, by establishing a twoway relation between pseudorandom encoding schemes and efficient invertible sampling algorithms, we reveal a connection between adaptively secure multiparty computation for randomized functionalities and questions in the domain of steganography.

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Section: Invertibilitymentioning

confidence: 69%

Section: New Results For Adaptively Secure Computationmentioning

confidence: 99%

Section: Overview Of Contributionsmentioning

confidence: 99%

Section: Invertibilitymentioning

confidence: 99%

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On Pseudorandom Encodings

Agrikola

Couteau

Ishai

et al. 2020

Theory of Cryptography

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“…Two-round MPC protocols in the malicious setting were first explored in [ 37 , 38 ], while recent years have witnessed exciting developments in two-round MPC [ 1 – 5 , 9 – 11 , 15 , 25 , 26 , 31 – 36 , 42 , 49 , 51 , 59 , 60 , 64 ]. The current state of the art can be summarized as follows: Garg and Srinivasan [ 33 ] and Benhamouda and Lin [ 9 ] showed how to balance between the optimal round complexity and minimal cryptographic assumptions for MPC in the broadcast model, by showing that every function can be computed with unanimous abort using two broadcast rounds, assuming two-round oblivious transfer (OT) and tolerating corruptions.…”

Section: Introductionmentioning

confidence: 99%

Broadcast-Optimal Two-Round MPC

Cohen

Garay

Zikas

2020

Lecture Notes in Computer Science

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An intensive effort by the cryptographic community to minimize the round complexity of secure multi-party computation (MPC) has recently led to optimal two-round protocols from minimal assumptions. Most of the proposed solutions, however, make use of a broadcast channel in every round, and it is unclear if the broadcast channel can be replaced by standard point-to-point communication in a round-preserving manner, and if so, at what cost on the resulting security. In this work, we provide a complete characterization of the trade-off between number of broadcast rounds and achievable security level for two-round MPC tolerating arbitrarily many active corruptions. Specifically, we consider all possible combinations of broadcast and point-to-point rounds against the three standard levels of security for maliciously secure MPC protocols, namely, security with identifiable, unanimous, and selective abort. For each of these notions and each combination of broadcast and point-to-point rounds, we provide either a tight feasibility or an infeasibility result of two-round MPC. Our feasibility results hold assuming two-round OT in the CRS model, whereas our impossibility results hold given any correlated randomness.

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