Smart contract

Last updated

A smart contract is a computer program or a transaction protocol that is intended to automatically execute, control or document events and actions according to the terms of a contract or an agreement. [1] [2] [3] [4] The objectives of smart contracts are the reduction of need for trusted intermediators, arbitration costs, and fraud losses, as well as the reduction of malicious and accidental exceptions. [5] [2] Smart contracts are commonly associated with cryptocurrencies, and the smart contracts introduced by Ethereum are generally considered a fundamental building block for decentralized finance (DeFi) and NFT applications. [6] [7]

Contents

The original Ethereum white paper by Vitalik Buterin in 2014 [8] describes the Bitcoin protocol as a weak version of the smart contract concept as originally defined by Nick Szabo, and proposed a stronger version based on the Solidity language, which is Turing complete. Since Bitcoin,[ clarification needed ] various cryptocurrencies have supported programming languages which allow for more advanced smart contracts between untrusted parties. [9]

A smart contract should not be confused with a smart legal contract, which refers to a traditional, natural-language, legally-binding agreement that has selected terms expressed and implemented in machine-readable code. [10] [11] [12]

Etymology

By 1996, Nick Szabo was using the term "smart contract" to refer to contracts which would be enforced by physical property (such as hardware or software) instead of by law. Szabo described vending machines as an example of this concept. [13] [14] In 1998, the term was used to describe objects in rights management service layer of the system The Stanford Infobus, which was a part of Stanford Digital Library Project. [1]

A smart contract does not typically constitute a valid binding agreement at law. [15] Proposals exist to regulate smart contracts. [10] [11] [12]

Smart contracts are not legal agreements, but instead transactions which are executed automatically by a computer program or a transaction protocol, [15] such as technological means for the automation of payment obligations [16] such as by transferring cryptocurrencies or other tokens. Some scholars have argued that the imperative or declarative nature of programming languages would impact the legal validity of smart contracts. [17]

Since the 2015 launch of the Ethereum blockchain, the term "smart contract" has been applied to general purpose computation that takes place on a blockchain. The US National Institute of Standards and Technology describes a "smart contract" as a "collection of code and data (sometimes referred to as functions and state) that is deployed using cryptographically signed transactions on the blockchain network". [18] In this interpretation a smart contract is any kind of computer program which uses a blockchain. A smart contract also can be regarded as a secured stored procedure, as its execution and codified effects (like the transfer of tokens between parties) cannot be manipulated without modifying the blockchain itself. In this interpretation, the execution of contracts is controlled and audited by the platform, not by arbitrary server-side programs connecting to the platform. [19] [20]

In 2018, a US Senate report said: "While smart contracts might sound new, the concept is rooted in basic contract law. Usually, the judicial system adjudicates contractual disputes and enforces terms, but it is also common to have another arbitration method, especially for international transactions. With smart contracts, a program enforces the contract built into the code." [21] States in the US which have passed legislation on the use of smart contracts include Arizona, [22] Iowa, [23] Nevada, [24] Tennessee, [25] and Wyoming. [26] In April 2020,

In April 2021, the UK Jurisdiction Taskforce (UKJT) published the Digital Dispute Resolution Rules (the Digital DR Rules) which was intended to enable the rapid resolution of blockchain and crypto legal disputes in Britain. [27]

Workings

Similar to a transfer of value on a blockchain, deployment of a smart contract on a blockchain occurs by sending a transaction from a wallet for the blockchain. [28] The transaction includes the compiled code for the smart contract as well as a special receiver address. [28] That transaction must then be included in a block that is added to the blockchain, at which point the smart contract's code will execute to establish the initial state of the smart contract. [28] Byzantine fault-tolerant algorithms secure the smart contract in a decentralized way from attempts to tamper with it. Once a smart contract is deployed, it cannot be updated. [29] Smart contracts on a blockchain can store arbitrary state and execute arbitrary computations. End clients interact with a smart contract through transactions. Such transactions with a smart contract can invoke other smart contracts. These transactions might result in changing the state and sending coins from one smart contract to another or from one account to another. [29]

The most popular blockchain for running smart contracts is Ethereum. [30] On Ethereum, smart contracts are typically written in a Turing-complete programming language called Solidity, [31] and compiled into low-level bytecode to be executed by the Ethereum Virtual Machine. [32] Due to the halting problem and other security problems, Turing-completeness is considered to be a risk and is deliberately avoided by languages like Vyper. [33] [34] Some of the other smart contract programming languages missing Turing-completeness are Simplicity, Scilla, Ivy and Bitcoin Script. [34] However, measurements in 2020 using regular expressions showed that only 35.3% of 53,757 Ethereum smart contracts at that time included recursions and loops — constructs connected to the halting problem. [35]

Several languages are designed to enable formal verification: Bamboo, IELE, Simplicity, Michelson (can be verified with Coq), [34] Liquidity (compiles to Michelson), Scilla, DAML and Pact. [33]

Notable examples of blockchain platforms supporting smart contracts include the following:
NameDescription
Ethereum Implements a Turing-complete language on its blockchain, a prominent smart contract framework [36]
Bitcoin Provides a Turing-incomplete script language that allows the creation of custom smart contracts on top of Bitcoin like multisignature accounts, payment channels, escrows, time locks, atomic cross-chain trading, oracles, or multi-party lottery with no operator. [37]
Binance Smart Chain A blockchain platform for smart contracts
Cardano A blockchain platform for smart contracts, using proof of stake
Solana A blockchain platform for smart contracts
Avalanche A blockchain platform for smart contracts
Tron A blockchain platform for smart contracts
EOS.IO A blockchain platform for smart contracts
Tezos A blockchain platform modifying its own set of rules with minimal disruption to the network through an on-chain governance model

Processes on a blockchain are generally deterministic in order to ensure Byzantine fault-tolerance. [38] Nevertheless, real world application of smart contracts, such as lotteries and casinos, require secure randomness. [39] In fact, blockchain technology reduces the costs for conducting of a lottery and is therefore beneficial for the participants. Randomness on blockchain can be implemented by using block hashes or timestamps, oracles, commitment schemes, special smart contracts like RANDAO [40] [41] and Quanta, as well as sequences from mixed strategy Nash equilibria. [38]

Applications

In 1998, Szabo proposed that smart contract infrastructure can be implemented by replicated asset registries and contract execution using cryptographic hash chains and Byzantine fault-tolerant replication. [42] Askemos implemented this approach in 2002 [43] [44] using Scheme (later adding SQLite [45] [46] ) as the contract script language. [47]

One proposal for using bitcoin for replicated asset registration and contract execution is called "colored coins". [48] Replicated titles for potentially arbitrary forms of property, along with replicated contract execution, are implemented in different projects.

As of 2015, UBS was experimenting with "smart bonds" that use the bitcoin blockchain [49] in which payment streams could hypothetically be fully automated, creating a self-paying instrument. [50]

Inheritance wishes could hypothetically be implemented automatically upon registration of a death certificate by means of smart contracts.[ according to whom? ] [51] [52] Birth certificates can also work together with smart contracts. [53] [54]

Chris Snook of Inc.com suggests smart contracts could also be used to handle real estate transactions and could be used in the field of title records and in the public register. [55] [56] [57] [58] [59]

Seth Oranburg and Liya Palagashvili argue that smart contracts could also be used in employment contracts, especially temporary employment contracts, which according to them would benefit the employer. [60] [61]

Smart contract on block chain technology for smart villages [62]

Security issues

The transactions data from a blockchain-based smart contract is visible to all users in the blockchain. The data provides cryptographic view of the transactions, however, this leads to a situation where bugs, including security holes, are visible to all yet may not be quickly fixed. [63] Such an attack, difficult to fix quickly, was successfully executed on The DAO in June 2016, draining approximately US$50 million worth of Ether at the time, while developers attempted to come to a solution that would gain consensus. [64] The DAO program had a time delay in place before the hacker could remove the funds; a hard fork of the Ethereum software was done to claw back the funds from the attacker before the time limit expired. [65] Other high-profile attacks include the Parity multisignature wallet attacks, and an integer underflow/overflow attack (2018), totaling over US$184 million. [66]

Issues in Ethereum smart contracts, in particular, include ambiguities and easy-but-insecure constructs in its contract language Solidity, compiler bugs, Ethereum Virtual Machine bugs, attacks on the blockchain network, the immutability of bugs and that there is no central source documenting known vulnerabilities, attacks and problematic constructs. [36]

Smart legal contracts are distinct from smart contracts. As mentioned above, a smart contract is not necessarily legally enforceable as a contract. On the other hand, a smart legal contract has all the elements of a legally enforceable contract in the jurisdiction in which it can be enforced and it can be enforced by a court or tribunal. Therefore, while every smart legal contract will contain some elements of a smart contract, not every smart contract will be a smart legal contract. [67]

There is no formal definition of a smart legal contract in the legal industry. [68]

A Ricardian contract is a type of smart legal contract.[ citation needed ]

See also

Related Research Articles

Solidity is a programming language for implementing smart contracts on various blockchain platforms, most notably, Ethereum. Solidity is licensed under GNU General Public License v3.0. Solidity was designed by Gavin Wood and developed by Christian Reitwiessner, Alex Beregszaszi, and several former Ethereum core contributors. Programs in Solidity run on Ethereum Virtual Machine or on compatible virtual machines.

<span class="mw-page-title-main">Cryptocurrency</span> Digital currency not reliant on a central authority

A cryptocurrency, crypto-currency, or crypto is a digital currency designed to work as a medium of exchange through a computer network that is not reliant on any central authority, such as a government or bank, to uphold or maintain it.

<span class="mw-page-title-main">Ethereum</span> Open-source blockchain computing platform

Ethereum is a decentralized blockchain with smart contract functionality. Ether is the native cryptocurrency of the platform. Among cryptocurrencies, ether is second only to bitcoin in market capitalization. It is open-source software.

A decentralized autonomous organization (DAO), sometimes called a decentralized autonomous corporation (DAC), is an organization managed in whole or in part by decentralized computer program, with voting and finances handled through a blockchain. In general terms, DAOs are member-owned communities without centralized leadership. The precise legal status of this type of business organization is unclear.

<span class="mw-page-title-main">Counterparty (platform)</span> Cryptocurrency platform

Counterparty is a peer-to-peer financial platform and a distributed, open source protocol built on top of the Bitcoin blockchain and network. It was one of the most well-known "Bitcoin 2.0" platforms in 2014, along with Mastercoin, Ethereum, Colored Coins, Ripple and BitShares.

A blockchain is a distributed ledger with growing lists of records (blocks) that are securely linked together via cryptographic hashes. Each block contains a cryptographic hash of the previous block, a timestamp, and transaction data. Since each block contains information about the previous block, they effectively form a chain, with each additional block linking to the ones before it. Consequently, blockchain transactions are irreversible in that, once they are recorded, the data in any given block cannot be altered retroactively without altering all subsequent blocks.

Hyperledger is an umbrella project of open source blockchains and related tools that the Linux Foundation started in December 2015. IBM, Intel, and SAP Ariba have contributed to support the collaborative development of blockchain-based distributed ledgers. It was renamed the Hyperledger Foundation in October 2021.

<span class="mw-page-title-main">Joseph Lubin (entrepreneur)</span> Canadian-American blockchain developer (born 1964)

Joseph Lubin is a Canadian-American businessman. He has founded and co-founded several companies, including the Swiss-based EthSuisse, contributing heavily to Ethereum, the decentralized cryptocurrency platform. Lubin is the founder of ConsenSys, a Brooklyn-based software production studio.

<span class="mw-page-title-main">The DAO</span> Decentralized business model based on the Ethereum blockchain

The DAO was a digital decentralized autonomous organization and a form of investor-directed venture capital fund. After launching in April 2016 via a token sale, it became one of the largest crowdfunding campaigns in history, but it ceased activity after much of its funds were taken in a hack in June 2016.

A decentralised application is an application that can operate autonomously, typically through the use of smart contracts, that run on a decentralized computing, blockchain or other distributed ledger system. Like traditional applications, DApps provide some function or utility to its users. However, unlike traditional applications, DApps operate without human intervention and are not owned by any one entity, rather DApps distribute tokens that represent ownership. These tokens are distributed according to a programmed algorithm to the users of the system, diluting ownership and control of the DApp. Without any one entity controlling the system, the application is therefore decentralised.

A smart bond is a specific type of an automated bond contract that uses the capabilities of blockchain databases that can operate as cryptographically-secure yet open and transparent general ledgers. This is sometimes referred to as Distributed Ledger Technology (DLT). It is one of a class of financial instruments known as a smart contract, "a computerized transaction protocol that executes the terms of a contract."

<span class="mw-page-title-main">Ethereum Classic</span> Blockchain computing platform

Ethereum Classic is a blockchain-based distributed computing platform that offers smart contract (scripting) functionality. It is open source and supports a modified version of Nakamoto consensus via transaction-based state transitions executed on a public Ethereum Virtual Machine (EVM).

<span class="mw-page-title-main">Cardano (blockchain platform)</span> Public blockchain platform

Cardano is a public blockchain platform. It is open-source and decentralized, with consensus achieved using proof of stake. It can facilitate peer-to-peer transactions with its internal cryptocurrency, ADA.

A cryptocurrency wallet is a device, physical medium, program or an online service which stores the public and/or private keys for cryptocurrency transactions. In addition to this basic function of storing the keys, a cryptocurrency wallet more often offers the functionality of encrypting and/or signing information. Signing can for example result in executing a smart contract, a cryptocurrency transaction, identification, or legally signing a 'document'.

<span class="mw-page-title-main">Gavin Wood</span> British computer programmer and entrepreneur

Gavin James Wood is an English computer scientist, a co-founder of Ethereum and creator of Polkadot and Kusama.

Distributed ledger technology law is not yet defined and recognized but an emerging field of law due to the recent dissemination of distributed ledger technology application in business and governance environment. Those smart contracts which were created through interaction of lawyers and developers and are intended to also be enforceable legal contracts are called smart legal contracts.

Cryptoeconomics is an evolving economic paradigm for a cross-disciplinary approach to the study of digital economies and decentralized finance (DeFi) applications. Cryptoeconomics integrates concepts and principles from traditional economics, cryptography, computer science, and game theory disciplines. Just as traditional economics provides a theoretical foundation for traditional financial services, cryptoeconomics provides a theoretical foundation for DeFi services bought and sold via fiat cryptocurrencies, and executed by smart contracts.

<span class="mw-page-title-main">Tezos</span> Decentralized open-source blockchain

Tezos is an open-source blockchain that can execute peer-to-peer transactions and serve as a platform for deploying smart contracts. The native cryptocurrency for the Tezos blockchain is the tez. The Tezos network achieves consensus using proof-of-stake. Tezos uses an on-chain governance model that enables the protocol to be amended when upgrade proposals receive a favorable vote from the community. Its testnet was launched in June 2018, and its mainnet went live in September 2018.

Decentralized finance offers financial instruments without relying on intermediaries such as brokerages, exchanges, or banks by using smart contracts on a blockchain, mainly Ethereum. DeFi platforms allow people to lend or borrow funds from others, speculate on price movements on assets using derivatives, trade cryptocurrencies, insure against risks, and earn interest in savings-like accounts. DeFi uses a layered architecture and highly composable building blocks. Some applications promote high-interest rates but are subject to high risk. Coding errors and hacks have been common in DeFi.

Chainlink is a decentralized blockchain oracle network built on Ethereum. The network is intended to be used to facilitate the transfer of tamper-proof data from off-chain sources to on-chain smart contracts. Its creators claim it can be used to verify whether the parameters of a smart contract are met in a manner independent from any of the contract's stakeholders by connecting the contract directly to real-world data, events, payments, and other inputs.

References

  1. 1 2 Röscheisen, Martin; Baldonado, Michelle; Chang, Kevin; Gravano, Luis; Ketchpel, Steven; Paepcke, Andreas (1998). "The Stanford InfoBus and its service layers: Augmenting the internet with higher-level information management protocols". Digital Libraries in Computer Science: The MeDoc Approach. Lecture Notes in Computer Science. Vol. 1392. Springer. pp. 213–230. doi:10.1007/bfb0052526. ISBN   978-3-540-64493-4.
  2. 1 2 Fries, Martin; P. Paal, Boris (2019). Smart Contracts (in German). Mohr Siebeck. ISBN   978-3-16-156911-1. JSTOR   j.ctvn96h9r.
  3. ↑ Savelyev, Alexander (14 December 2016). "Contract Law 2.0: "Smart" Contracts As the Beginning of the End of Classic Contract Law". Social Science Research Network. SSRN   2885241. Archived from the original on 24 March 2020. Retrieved 24 May 2020.
  4. ↑ Tapscott, Don; Tapscott, Alex (May 2016). The Blockchain Revolution: How the Technology Behind Bitcoin is Changing Money, Business, and the World. Portfolio/Penguin. pp. 72, 83, 101, 127. ISBN   978-0670069972.
  5. ↑ Szabo, Nick (1997). "View of Formalizing and Securing Relationships on Public Networks | First Monday". First Monday. doi: 10.5210/fm.v2i9.548 . S2CID   33773111. Archived from the original on 2022-04-10. Retrieved 2020-05-24.
  6. ↑ Zhou, Haozhe; Milani Fard, Amin; Makanju, Adetokunbo (2022-05-27). "The State of Ethereum Smart Contracts Security: Vulnerabilities, Countermeasures, and Tool Support". Journal of Cybersecurity and Privacy. 2 (2): 358–378. doi: 10.3390/jcp2020019 . ISSN   2624-800X.
  7. ↑ "All You Need to Know About NFT Smart Contracts". Binance.com. Binance. Archived from the original on 26 September 2022. Retrieved 26 September 2022.
  8. ↑ "White Paper· ethereum/wiki Wiki · GitHub". GitHub . Archived from the original on 11 January 2014.
  9. ↑ Alharby, Maher; van Moorsel, Aad (26 August 2017). "Blockchain-based Smart Contracts: A Systematic Mapping Study". Computer Science & Information Technology: 125–140. arXiv: 1710.06372 . doi:10.5121/csit.2017.71011. ISBN   9781921987700. S2CID   725413.
  10. 1 2 Cannarsa, Michel (1 December 2018). "Interpretation of Contracts and Smart Contracts: Smart Interpretation or Interpretation of Smart Contracts?". European Review of Private Law. 26 (6): 773–785. doi:10.54648/ERPL2018054. S2CID   188017977. Archived from the original on 10 August 2020. Retrieved 20 September 2020.
  11. 1 2 Drummer, Daniel; Neumann, Dirk (5 August 2020). "Is code law? Current legal and technical adoption issues and remedies for blockchain-enabled smart contracts". Journal of Information Technology. 35 (4): 337–360. doi:10.1177/0268396220924669. ISSN   0268-3962. S2CID   225409384. Archived from the original on 9 March 2021. Retrieved 20 September 2020.
  12. 1 2 Filatova, Nataliia (1 September 2020). "Smart contracts from the contract law perspective: outlining new regulative strategies". International Journal of Law and Information Technology. 28 (3): 217–242. doi:10.1093/ijlit/eaaa015. ISSN   0967-0769. Archived from the original on 18 January 2022. Retrieved 20 September 2020.
  13. ↑ Morris, David Z. (21 January 2014). "Bitcoin is not just digital currency. It's Napster for finance". Fortune . Archived from the original on 20 October 2014. Retrieved 7 November 2018.
  14. ↑ Schulpen, Ruben R.W.H.G. (1 August 2018). "Smart contracts in the Netherlands - University of Tilburg". uvt.nl. Twente University. Archived from the original on 19 February 2021. Retrieved 26 October 2019.
  15. 1 2 Mik, Eliza, Smart Contracts: A Requiem (December 7, 2019). Journal of Contract Law (2019) Volume 36 Part 1 at p 72
  16. ↑ J Cieplak, S Leefatt, ‘Smart Contracts: A Smart Way To Automate Performance’ (2017) 1 Georgia L & Tech Rev 417
  17. ↑ Governatori, Guido; Idelberger, Florian; Milosevic, Zoran; Riveret, Regis; Sartor, Giovanni; Xu, Xiwei (2018). "On legal contracts, imperative and declarative smart contracts, and blockchain systems". Artificial Intelligence and Law. 26 (4): 33. doi:10.1007/s10506-018-9223-3. S2CID   3663005.
  18. ↑ D J Yaga et al., Blockchain Technology Overview, National Institute of Standards and Technology Internal/Interagency Report 8202, 2018, p 54, cited in Mik, Eliza, Smart Contracts: A Requiem (December 7, 2019). Journal of Contract Law (2019) Volume 36 Part 1 at p 71
  19. ↑ Vo, Hoang Tam; Kundu, Ashish; Mohania, Mukesh (2018). "Research Directions in Blockchain Data Management and Analytics" (PDF). Advances in Database Technology - Extending Database Technology (EDBT). 21. OpenProceedings: 446. Archived (PDF) from the original on 2019-10-02. Retrieved 2019-10-02. Some distributed ledger technologies support an additional capability called a smart contract, which is similar to the concept of stored procedure in classical relational databases to some extent. Smart contracts allow the shared business processes within a business network to be standardised, automated and enforced via computer programs to increase the integrity of the ledger.
  20. ↑ Huckle, Steve; Bhattacharya, Rituparna; White, Martin; Beloff, Natalia (2016). "Internet of Things, Blockchain and Shared Economy Applications". Procedia Computer Science. 98. Elsevier B.V.: 463. doi: 10.1016/j.procs.2016.09.074 . Firstly, that total quantity of BTC in a transaction's inputs must cover the total number of BTC in the outputs. That rule behaves similarly to a database stored procedure, except that it is impossible to circumvent. Secondly, BTC transactions use public-private key cryptography. That makes BTC act like a database with a publicly auditable per-row permission scheme.
  21. ↑ Chapter 9: Building a Secure Future, One blockchain at a time Archived 2020-05-14 at the Wayback Machine , US Senate Joint Economic Committee, March 2018.
  22. ↑ "Arizona HB2417 - 2017 - Fifty-third Legislature 1st Regular". LegiScan. Archived from the original on 2017-04-28. Retrieved 2020-09-16.
  23. ↑ "Iowa House approves bills to facilitate broadband, cryptocurrency". www.thegazette.com. Archived from the original on 2021-04-15. Retrieved 2021-04-15.
  24. ↑ Hyman Gayle M, Digesti, Matthew P New Nevada legislation recognizes blockchain and smart contract terminologies Archived 2018-09-10 at the Wayback Machine August 2017, Nevada Lawyer
  25. ↑ Tom, Daniel (22 September 2020). "Smart Contract Bill Tennessee" (PDF). Archived (PDF) from the original on 2 October 2020. Retrieved 22 September 2020.
  26. ↑ Wyoming, Legislature (26 February 2019). "Wyoming - Smart Contract". Archived from the original on 28 January 2019. Retrieved 26 September 2020.
  27. ↑ Morgan, Herbert Smith Freehills LLP-Charlie; Parker, Chris; Livingston, Dorothy; Naish, Vanessa; Tevendale, Craig (23 April 2021). "Arbitration of digital disputes in smart contracts and the release of the digital dispute resolution rules from the UK jurisdiction taskforce | Lexology". www.lexology.com. Archived from the original on 2021-04-25. Retrieved 2021-04-25.
  28. 1 2 3 Soloro, Kevin; Kanna, Randall; Hoover, David (December 2019). Hands-On Smart Contract Development With Solidity and Ethereum: From Fundamentals to Deployment. California, U.S.A.: O'Reilly. p. 73. ISBN   978-1-492-04526-7. Archived from the original on 25 October 2023. Retrieved 1 November 2020.
  29. 1 2 Sergey, Ilya; Nagaraj, Vaivaswatha; Johannsen, Jacob; Kumar, Amrit; Trunov, Anton; Hao, Ken Chan Guan (10 October 2019). "Safer smart contract programming with Scilla". Proceedings of the ACM on Programming Languages. 3 (OOPSLA): 1–30. doi: 10.1145/3360611 . ISSN   2475-1421.
  30. ↑ Alharby, Maher; van Moorsel, Aad (26 August 2017). "Blockchain-based Smart Contracts: A Systematic Mapping Study". Computer Science & Information Technology: 125–140. arXiv: 1710.06372 . doi: 10.5121/csit.2017.71011 . ISBN   9781921987700.
  31. ↑ Wohrer, Maximilian; Zdun, Uwe (20 March 2018). "Smart contracts: Security patterns in the ethereum ecosystem and solidity". 2018 International Workshop on Blockchain Oriented Software Engineering (IWBOSE). pp. 2–8. doi:10.1109/IWBOSE.2018.8327565. ISBN   978-1-5386-5986-1. S2CID   4567923. Archived from the original on 9 October 2020. Retrieved 4 October 2020.
  32. ↑ Perez, Daniel; Livshits, Benjamin (17 October 2020). "Smart Contract Vulnerabilities: Vulnerable Does Not Imply Exploited". arXiv: 1902.06710 [cs.CR].
  33. 1 2 Harz, Dominik; Knottenbelt, William (31 October 2018). "Towards Safer Smart Contracts: A Survey of Languages and Verification Methods". arXiv: 1809.09805 [cs.CR].
  34. 1 2 3 Tyurin, A.V.; Tyuluandin, I.V.; Maltsev, V.S.; Kirilenko, I.A.; Berezun, D.A. (2019). "Overview of the Languages for Safe Smart Contract Programming". Proceedings of the Institute for System Programming of the RAS. 31 (3): 157–176. doi: 10.15514/ispras-2019-31(3)-13 . S2CID   203179644.
  35. ↑ Jansen, Marc; Hdhili, Farouk; Gouiaa, Ramy; Qasem, Ziyaad (2020). "Do Smart Contract Languages Need to be Turing Complete?". Blockchain and Applications. Advances in Intelligent Systems and Computing. Vol. 1010. Springer International Publishing. pp. 19–26. doi:10.1007/978-3-030-23813-1_3. ISBN   978-3-030-23812-4. S2CID   195656195.
  36. 1 2 Atzei, Nicola; Bartoletti, Massimo; Cimoli, Tiziana (2017), "A survey of attacks on Ethereum smart contracts" (PDF), 6th International Conference on Principles of Security and Trust (POST), European Joint Conferences on Theory and Practice of Software, archived (PDF) from the original on 2017-07-10, retrieved 2017-06-20
  37. ↑ Atzei, Nicola; Bartoletti, Massimo; Cimoli, Tiziana; Lande, Stefano; Zunino, Roberto (2018), "SoK: unraveling Bitcoin smart contracts" (PDF), 7th International Conference on Principles of Security and Trust (POST), European Joint Conferences on Theory and Practice of Software, archived (PDF) from the original on 2018-02-23, retrieved 2018-02-22
  38. 1 2 Chatterjee, Krishnendu; Goharshady, Amir Kafshdar; Pourdamghani, Arash (21 February 2019). "Probabilistic Smart Contracts: Secure Randomness on the Blockchain". arXiv: 1902.07986 [cs.GT].
  39. ↑ Chen, Tai-yuan; Huang, Wei-ning; Kuo, Po-chun; Chung, Hao (6 August 2020). "Method for Generating Secure Randomness on Blockchain" . Retrieved 28 August 2020.
  40. ↑ Jia, Zhifeng; Chen, Rui; Li, Jie (2019). "DeLottery: A Novel Decentralized Lottery System Based on Blockchain Technology". Proceedings of the 2019 2nd International Conference on Blockchain Technology and Applications. pp. 20–25. doi:10.1145/3376044.3376049. ISBN   9781450377430. S2CID   207880557.
  41. ↑ "randao/randao". randao. 10 July 2020. Archived from the original on 10 August 2020. Retrieved 10 July 2020.
  42. ↑ Nick Szabo (1998). "Secure Property Titles with Owner Authority". Archived from the original on January 15, 2014. Retrieved January 12, 2014.
  43. ↑ Jörg F. Wittenberger (2002). Askemos a distributed settlement. Proceedings of International Conference on Advances in Infrastructure for e-Business, e-Education, e-Science, and e-Medicine on the Internet (SSGRR), L’Aquila. Archived from the original on 2018-07-01. Retrieved 2017-05-25.
  44. ↑ "Proceedings of International Conference on Advances in Infrastructure for e-Business, e-Education, e-Science, and e-Medicine on the Internet" (PDF). Archived from the original (PDF) on 2017-10-26. Retrieved 2017-05-25.
  45. ↑ Martin Möbius (2009). Erstellung eines Archivierungskonzepts für die Speicherung rückverfolgbarer Datenbestände im Askemos-System (Thesis). Hochschule Mittweida. Archived from the original on 2018-07-01. Retrieved 2017-05-25.
  46. ↑ Tom-Steve Watzke (2010). "Entwicklung einer Datenbankschnittstelle als Grundlage für Shop-Systeme unter dem Betriebssystem Askemos". Archived from the original on 2018-07-01. Retrieved 2017-05-25.
  47. ↑ RA Markus Heinker (2007). "Beweiswürdigung elektronischer Dokumente im Zivilprozess unter vergleichender Betrachtung von qualifizierten elektronischen Signaturen nach dem Signaturgesetz und dem Askemos-Verfahren". Archived from the original on 2018-07-01. Retrieved 2017-05-25.
  48. ↑ Hal Hodson (20 November 2013). "Bitcoin moves beyond mere money". New Scientist. Archived from the original on 5 July 2015. Retrieved 12 January 2014.
  49. ↑ Ross, Rory (2015-09-12). "Smart Money: Blockchains Are the Future of the Internet". Newsweek . Archived from the original on 2016-07-10. Retrieved 2016-05-27.
  50. ↑ Wigan, David (2015-06-11). "Bitcoin technology will disrupt derivatives, says banker". IFR Asia. Archived from the original on 2016-06-29. Retrieved 2016-05-27.
  51. ↑ "How blockchain technology could change our lives" (PDF). Archived (PDF) from the original on 2017-03-30. Retrieved 2024-05-24.
  52. ↑ "Blockchain and AI are coming to kill these 4 business verticals". Archived from the original on 2017-12-22. Retrieved 2024-05-24.
  53. ↑ Blockchain for Digital Governments
  54. ↑ "Blockchain Based Framework for Document Authentication". Archived from the original on 2021-05-12. Retrieved 2024-05-24.
  55. ↑ Snook, Chris J. (31 October 2017). "Blockchain and Artificial Intelligence Are Coming to Kill These 4 Small Business Verticals". Inc.com. Archived from the original on 22 December 2017. Retrieved 25 January 2022.
  56. ↑ "The Bitfury Group and Government of Republic of Georgia Expand Blockchain Pilot" (PDF). Archived (PDF) from the original on 2021-05-26. Retrieved 2021-05-26.
  57. ↑ "A BLOCKCHAIN - Journals Gateway". Archived from the original on 2021-03-03. Retrieved 2021-05-26.
  58. ↑ "Digital Transformation: Blockchain and Land Titles" (PDF). Archived (PDF) from the original on 2021-06-21. Retrieved 2021-05-26.
  59. ↑ "Ukraine launches big blockchain deal with tech firm Bitfury". Reuters . 17 April 2017. Archived from the original on 2023-01-24.
  60. ↑ Oranburg, Seth; Palagashvili, Liya (22 October 2018). "The Gig Economy, Smart Contracts, and Disruption of Traditional Work Arrangements". Search eLibrary. doi:10.2139/ssrn.3270867. S2CID   216803648. SSRN   3270867. Archived from the original on 20 February 2022. Retrieved 25 January 2022.
  61. ↑ "A blockchain-based decentralized system for proper handling of temporary employment contracts". Archived from the original on 2023-10-15. Retrieved 2024-05-24.
  62. ↑ Kaur, Parminder; Parashar, Anshu (2022-06-01). "A Systematic Literature Review of Blockchain Technology for Smart Villages". Archives of Computational Methods in Engineering. 29 (4): 2417–2468. doi:10.1007/s11831-021-09659-7. ISSN   1886-1784. PMC   8549431 . PMID   34720578.
  63. ↑ Peck, M. (28 May 2016). "Ethereum's $150-Million Blockchain-Powered Fund Opens Just as Researchers Call For a Halt". IEEE Spectrum . Institute of Electrical and Electronics Engineers. Archived from the original on 30 May 2016. Retrieved 2 February 2020.
  64. ↑ DuPont, Quinn (2017). "Experiments in Algorithmic Governance: A history and ethnography of "The DAO", a failed Decentralized Autonomous Organization" (PDF). Archived from the original (PDF) on 2017-07-30. Retrieved 29 July 2017.
  65. ↑ Coy, Peter; Kharif, Olga (25 August 2016). "This Is Your Company on Blockchain". Bloomberg Businessweek. Archived from the original on 2016-09-14. Retrieved 2016-12-05.
  66. ↑ Praitheeshan, Purathani; Pan, Lei; Yu, Jiangshan; Liu, Joseph; Doss, R. (2019). "Security Analysis Methods on Ethereum Smart Contract Vulnerabilities: A Survey". arXiv: 1908.08605 [cs.CR].
  67. ↑ Whitepaper: Smart Contracts and Distributed Ledger – A Legal Perspective Archived 2018-04-24 at the Wayback Machine , 5.
  68. ↑ Whitepaper: Smart Contracts and Distributed Ledger – A Legal Perspective Archived 2018-04-24 at the Wayback Machine , 3.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.