Secure Multiparty Computations on Bitcoin

By Marcin Andrychowicz, Stefan Dziembowski, Daniel Malinowski, Lukasz Mazurek. 2014

456 citations recorded by the source corpus.

Bit coin is a decentralized digital currency, introduced in 2008, that has recently gained noticeable popularity. Its main features are: (a) it lacks a central authority that controls the transactions, (b) the list of transactions is publicly available, and (c) its syntax allows more advanced transactions than simply transferring the money. The goal of this paper is to show how these properties of Bit coin can be used in the area of secure multiparty computation protocols (MPCs). Firstly, we show that the Bit coin system provides an attractive way to construct a version of "timed commitments", where the committer has to reveal his secret within a certain time frame, or to pay a fine. This, in turn, can be used to obtain fairness in some multiparty protocols. Secondly, we introduce a concept of multiparty protocols that work "directly on Bit coin". Recall that the standard definition of the MPCs guarantees only that the protocol "emulates the trusted third party". Hence ensuring that the inputs are correct, and the outcome is respected is beyond the scope of the definition. Our observation is that the Bit coin system can be used to go beyond the standard "emulation-based" definition, by constructing protocols that link their inputs and the outputs with the real Bit coin transactions. As an instantiation of this idea we construct protocols for secure multiparty lotteries using the Bit coin currency, without relying on a trusted authority (one of these protocols uses the Bit coin-based timed commitments mentioned above). Our protocols guarantee fairness for the honest parties no matter how the loser behaves. For example: if one party interrupts the protocol then her money is transferred to the honest participants. Our protocols are practical (to demonstrate it we performed their transactions in the actual Bit coin system), and can be used in real life as a replacement for the online gambling sites. We think that this paradigm can have also other applications. We discuss some of them.

Subfields: Artificial Intelligence, Information Systems

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Citations in the corpus

Ekiden: A Platform for Confidentiality-Preserving, Trustworthy, and Performant Smart Contracts (2018, neutral): “Poker applications have been used as a benchmark application for prior systems using blockchains and secure multi-party computation, known as mental poker [9, 14, 48, 49].”
Ouroboros Genesis: Composable Proof-of-Stake Blockchains with Dynamic Availability (2018, background): “For example, a number of recent works [1, 2, 6, 27, 28] describe how blockchain-based cryptocurrencies can be used to obtain a natural notion of fairness in multi-party computation against dishonest majorities; or to allow parties to play games of chance—e.”
Security and Privacy on Blockchain (2019, methodology): “Andrychow-icz et al. designed and implemented secure multiparty computation protocols on Bitcoin system in 1:29 2014 [10].”
Bitcoin, Blockchain and Fintech: a systematic review and case studies in the supply chain (2019, unknown): “Bitcoin application domain References Number of referencess % Accounting and financial regulation (Ram, Maroun, and Garnett 2016; Gross, Hoelscher, and Reed 2015; Antonikova 2015; Harrison and Mano 2015; Jacobs 2011, Kurihara and Fukushima 2017; Pakrou and Amir 2016; Irwin and Milad 2016; Mikolajewi”
Proof of Activity: Extending Bitcoin's Proof of Work via Proof of Stake [Extended Abstract]y (2014, background): “As a means of exchange, Bitcoin facilitates fast worldwide transactions with trivial fees and without identity theft risks.”
A Survey of Attacks on Ethereum Smart Contracts (SoK) (2017, background): “Alternative solutions to this problem are based on timed commitment protocols [25, 29].”
CrowdBC: A Blockchain-Based Decentralized Framework for Crowdsourcing (2019, background): “Some works have been done to achieve time-locked blockchain deposit protocol [51], [52], [53].”
Bitcoin and Beyond: A Technical Survey on Decentralized Digital Currencies (2016, methodology): “Other use cases include coin tosses [238], lotteries [239], or decentralized poker [240], This works without a central entity and without the need to trust each other, that is, secure multi-party computations (MPC).”
Step by Step Towards Creating a Safe Smart Contract: Lessons and Insights from a Cryptocurrency Lab (2016, background): “A line of work in both academia and industry has attempted to design various smart contract applications in a way that retroﬁts Bitcoin’s scripting language [6,8,19,20].”
TumbleBit: An Untrusted Bitcoin-Compatible Anonymous Payment Hub (2017, methodology): “We follow prior works that use Bitcoin for fair exchange [4], [24], [25] and treat the blockchain as a trusted public ledger.”
Integrated Blockchain and Edge Computing Systems: A Survey, Some Research Issues and Challenges (2019, background): “2) Secure Multiparty Computations on Blockchain: An early work on the integration of blockchain and computation in [74] studies how to do Multiparty Computation (MPC) on Bitcoin.”
SoK: Research Perspectives and Challenges for Bitcoin and Cryptocurrencies (2015, background): “[5] reported needing to submit their complex multiparty lottery scripts directly to the Eligius mining pool.”
Amortizing Secure Computation with Penalties (2016, background): “…such that for every non-uniform probabilistic polynomial-time adversary Z , Notation: session identiﬁer sid , an n -input, n (cid:48) -output function f , a hard-coded ordering of outputs χ = ( χ 1 ,..., χ n (cid:48) ) , parties P 1 ,..., P n , adversary S that corrupts parties { P s } s ∈ C , set”
Demystifying Incentives in the Consensus Computer (2015, methodology): “Since the rise of Bitcoin, a new line of work on repur-posing the blockchain for other applications has been initiated [19, 21, 16, 20].”
Enigma: Decentralized Computation Platform with Guaranteed Privacy (2015, background): “Using Bitcoin security deposits for punishing malicious nodes in MPC has been investigated by several scholars recently [22, 23].”
Instantaneous Decentralized Poker (2017, result): “We present new protocols that rely on stateful contracts instead of Bitcoin transactions, and thereby improve upon the previous results in several ways.”