Improvements to Secure Computation with Penalties

Kumaresan, Ranjit; Vaikuntanathan, Vinod; Vasudevan, Prashant Nalini

doi:10.1145/2976749.2978421

Cited by 72 publications

(45 citation statements)

References 33 publications

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“…In order to limit the role of a TTP [2,5] proposed the distinction between the optimistic and pessimistic case of fair exchange. Since the emerge of blockchain technologies, smart contracts are considered as TTP, and there are numerous works that use smart contracts to improve on the fairness properties of cryptographic protocols [1,3,[14][15][16].…”

Section: Related Workmentioning

confidence: 99%

OptiSwap: Fast Optimistic Fair Exchange

Eckey

Faust

Schlosser

2020

Proceedings of the 15th ACM Asia Conference on Computer and Communications Security

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Selling digital commodities securely over the Internet is a challenging task when Seller and Buyer do not trust each other. With the advent of cryptocurrencies, one prominent solution for digital exchange is to rely on a smart contract as a trusted arbiter that fairly resolves disputes when Seller and Buyer disagree. Such protocols have an optimistic mode, where the digital exchange between the parties can be completed with only minimal interaction with the smart contract. In this work we present OptiSwap, a new smart contract based fair exchange protocol that significantly improves the optimistic case of smart contract based fair exchange protocols. In particular, OptiSwap has almost no overhead in communication complexity, and improves on the computational overheads of the parties compared to prior solutions. An additional feature of OptiSwap is a protection mechanism against so-called grieving attacks, where an adversary attempts to violate the financial fairness of the protocol by forcing the honest party to pay fees. We analyze OptiSwap's security in the UC model and provide benchmark results over Ethereum. CCS CONCEPTS • Security and privacy → Cryptography.

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Section: Related Workmentioning

confidence: 99%

OptiSwap: Fast Optimistic Fair Exchange

Eckey

Faust

Schlosser

2020

Proceedings of the 15th ACM Asia Conference on Computer and Communications Security

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“…Both approaches require a number of rounds depending on the circuit depth, but achieve a notion of fairness. Fairness can also be achieved in off-chain multi-party protocols using incentives, e.g., by crypto-currencies, or trusted hardware on the blockchain [11,12,23,39,40]. In contrast, BOREALIS assumes honest majority, but optimizes efficiency.…”

Section: Related Workmentioning

confidence: 99%

BOREALIS: Building Block for Sealed Bid Auctions on Blockchains

Blaß

Kerschbaum

2020

Proceedings of the 15th ACM Asia Conference on Computer and Communications Security

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We focus on securely computing the ranks of sealed integers distributed among parties. For example, we securely compute the largest or smallest integer, the median, or in general the th-ranked integer. Such computations are a useful building block to securely implement a variety of sealed-bid auctions. Our objective is efficiency, specifically low interactivity between parties to support blockchains or other scenarios where multiple rounds are timeconsuming. Hence, we dismiss powerful, yet highly-interactive MPC frameworks and propose BOREALIS, a special-purpose protocol for secure computation of ranks among integers. BOREALIS uses additively homomorphic encryption to implement core comparisons, but computes under distinct keys, chosen by each party to optimize the number of rounds. By carefully combining cryptographic primitives, such as ECC Elgamal encryption, encrypted comparisons, ciphertext blinding, secret sharing, and shuffling, BO-REALIS sets up systems of multi-scalar equations which we efficiently prove with Groth-Sahai ZK proofs. Therewith, BOREALIS implements a multi-party computation of pairwise comparisons and rank zero-knowledge proofs secure against malicious adversaries. BOREALIS completes in at most 4 rounds which is constant in both bit length ℓ of integers and the number of parties. This is not only asymptotically optimal, but surpasses generic constantround secure multi-party computation protocols, even those based on shared-key fully homomorphic encryption. Furthermore, our implementation shows that BOREALIS is very practical. Its main bottleneck, ZK proof computations, is small in practice. Even for a large number of parties (= 200) and high-precision integers (ℓ = 32), computation time of all proofs is less than a single Bitcoin block interval. CCS CONCEPTS • Security and privacy → Cryptography.

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“…An approach is to penalize a faulty participant upon aborting in an MPC, hence make the adversary lose some digital cash in proportion to their actions. For instance, [36] and [37] require the adversary to make deposits and forfeit them upon dropping out. Unfortunately those protocols are not usable in our scenario.…”

Section: Beyond Security-with-abortmentioning

confidence: 99%

FuturesMEX: Secure, Distributed Futures Market Exchange

Massacci

Ngo

Nie

et al. 2018

2018 IEEE Symposium on Security and Privacy (SP)

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In a Futures-Exchange, such as the Chicago Mercantile Exchange, traders buy and sell contractual promises (futures) to acquire or deliver, at some future pre-specified date, assets ranging from wheat to crude oil and from bacon to cash in a desired currency. The interactions between economic and security properties and the exchange's essentially non-monotonic security behavior; a valid trader's valid action can invalidate other traders' previously valid positions, are a challenge for security research. We show the security properties that guarantee an Exchange's economic viability (availability of trading information, liquidity, confidentiality of positions, absence of price discrimination, riskmanagement) and an attack when traders' anonymity is broken. We describe all key operations for a secure, fully distributed Futures-Exchange, hereafter referred to as simply the 'Exchange'. Our distributed, asynchronous protocol simulates the centralized functionality under the assumptions of anonymity of the physical layer and availability of a distributed ledger. We consider security with abort (in absence of honest majority) and extend it to penalties. Our proof of concept implementation and its optimization (based on zk-SNARKs and SPDZ) demonstrate that the computation of actual trading days (along Thomson-Reuters Tick History DB) is feasible for low-frequency markets; however, more research is needed for high-frequency ones. FuturesMEX technologies are the object of the following patent applications: US62/625,428 and PG448130GB. 1 On the CME, futures contracts range from bushels of corn to Euro/US$ exchange rates. Recently, CBOE and CME launched Bitcoin futures markets. These are 'cash-futures', that is as they are settled in cash. Eurodollars futures are the largest world market by notional volume: in quadrillions of dollars/year.

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Improvements to Secure Computation with Penalties

Cited by 72 publications

References 33 publications

OptiSwap: Fast Optimistic Fair Exchange

OptiSwap: Fast Optimistic Fair Exchange

BOREALIS: Building Block for Sealed Bid Auctions on Blockchains

FuturesMEX: Secure, Distributed Futures Market Exchange

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