Two Round Information-Theoretic MPC with Malicious Security

Ananth, Prabhanjan; Choudhuri, Arka Rai; Goel, Aarushi; Jain, Abhishek

doi:10.1007/978-3-030-17656-3_19

Cited by 18 publications

(24 citation statements)

References 29 publications

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“…The above state of affairs motivated a line of work investigating the effect in the round complexity of removing the assumption of broadcast from two-round MPC protocols [ 2 , 4 , 49 , 51 , 60 ]. In order to do so, however, one needs to settle for weaker security definitions.…”

Section: Introductionmentioning

confidence: 99%

“…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. In the honest-majority setting, Ananth et al [ 2 ] and Applebaum et al [ 4 ] showed that security with selective abort can be achieved using two point-to-point rounds assuming OWF. Patra and Ravi [ 60 ] showed that in the plain model (without any setup assumptions, such as a PKI) security with unanimous abort cannot be achieved in two point-to-point rounds, and even if the first round can use a broadcast channel.…”

Section: Introductionmentioning

confidence: 99%

“…In the honest-majority setting, Ananth et al [ 2 ] and Applebaum et al [ 4 ] showed that security with selective abort can be achieved using two point-to-point rounds assuming OWF.…”

Section: Introductionmentioning

confidence: 99%

“…Next, we proceed to provide matching upper bounds, showing that security with unanimous abort is feasible when the second round is over broadcast (even if the first round is over point-to-point), and that security with selective abort can be achieved when both rounds are over point-to-point channels. Our results are based on the compiler of Ananth et al [ 2 ], who focused on information-theoretic security of two-round MPC in the honest-majority setting. 3 Ananth et al [ 2 ], initially adjusted the two-round protocol from [ 1 ] to provide information-theoretic security with unanimous abort in the broadcast model (for circuits), and then compiled it to provide security with selective abort over point-to-point channels.…”

Section: Introductionmentioning

confidence: 99%

“…Compiling Two-Broadcast-Round Protocols. We start by presenting an adaptation of the compiler from [ 2 ] to the dishonest-majority setting. Let be a two-round MPC protocol in the broadcast model that is secure with unanimous abort.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

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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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…In the honest-majority setting, Ananth et al [ 2 ] and Applebaum et al [ 4 ] showed that security with selective abort can be achieved using two point-to-point rounds assuming OWF.…”

Section: Introductionmentioning

confidence: 99%