A Survey of Attacks on Ethereum Smart Contracts SoK
22 Apr 2017-Vol. 10204, pp 164-186
TL;DR: This work analyses the security vulnerabilities of Ethereum smart contracts, providing a taxonomy of common programming pitfalls which may lead to vulnerabilities, and shows a series of attacks which exploit these vulnerabilities, allowing an adversary to steal money or cause other damage.
Abstract: Smart contracts are computer programs that can be correctly executed by a network of mutually distrusting nodes, without the need of an external trusted authority. Since smart contracts handle and transfer assets of considerable value, besides their correct execution it is also crucial that their implementation is secure against attacks which aim at stealing or tampering the assets. We study this problem in Ethereum, the most well-known and used framework for smart contracts so far. We analyse the security vulnerabilities of Ethereum smart contracts, providing a taxonomy of common programming pitfalls which may lead to vulnerabilities. We show a series of attacks which exploit these vulnerabilities, allowing an adversary to steal money or cause other damage.
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TL;DR: This study, which is the first to not only carry out a relatively comprehensive investigation of the transaction data recorded in Ethereum but also probe the statistical laws underlying the transaction relationships from the perspective of network science, finds that several transaction features exhibit a heavy-tailed property.
57 citations
TL;DR: A novel Food Trading System with COnsortium blockchaiN (FTSCON) to improve trust and security issues in transactions, which uses consortium blockchain technology to set permission and authentication for different roles in food transaction, which meet the challenge of the privacy protection of multi-stakeholders.
Abstract: Conventional food trading platforms face several issues, such as quickly to find trading objects and protect the reliability of transaction information With e-commerce developing rapidly, food trading has also recently shifted to the online domain Blockchain has changed many industries owing to its robustness, decentralization and end-to-end credibility This paper proposes a novel Food Trading System with COnsortium blockchaiN (FTSCON) to improve trust and security issues in transactions It uses consortium blockchain technology to set permission and authentication for different roles in food transaction, which meet the challenge of the privacy protection of multi-stakeholders The algorithm of optimized transaction combination is designed for the purpose of helping users find suitable transaction objects It can choose the optimized trading portfolio for buyers The online double auction mechanism is used to eliminate competition And the improved PBFT (iPBFT) is used to enhance efficiency of system Moreover, a smart-contract life- cycle management method is introduced, and security analysis shows that FTSCON improves transaction security and privacy protection Experiment results based on a series of data indicate that the proposed algorithm can achieve profit improvement of merchants
56 citations
27 May 2019
TL;DR: This paper proposes a precise and generally applicable technique, VULTRON, which can detect irregular transactions due to various types of adversarial exploits and reports preliminary results applying the technique to real-world case studies.
Abstract: Despite the high stakes involved, smart contracts are often developed in an undisciplined way thus far. The existence of vulnerabilities compromises the security and reliability of smart contracts, and endangers the trust of participants in their ongoing businesses. Existing vulnerability detection techniques are often designed case-by-case, making them difficult to generalize. In this paper, we design general principles for detecting vulnerable smart contracts. Our key insight is that almost all the existing transaction-related vulnerabilities are due to the mismatch between the actual transferred amount and the amount reflected on the contract's internal bookkeeping. Based on this, we propose a precise and generally applicable technique, VULTRON, which can detect irregular transactions due to various types of adversarial exploits. We also report preliminary results applying our technique to real-world case studies.
56 citations
Cites background from "A Survey of Attacks on Ethereum Sma..."
...Within a chain of nested calls, there could be two types of exception handling mechanisms [15]: (1) If all the functions in the chain are direct calls, the execution stops and all side effects are reverted, including transfers of Ether....
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01 Sep 2019
TL;DR: The main aim of this paper is to present the current state of the art on blockchain‐based medical healthcare system and clearly discussed several existing works on the same domain and also presented a comparative study among the published works.
56 citations
Posted Content•
TL;DR: This work presents eThor, the first sound and automated static analyzer for EVM bytecode, which is based on an abstraction of the EVMbytecode semantics based on Horn clauses, and demonstrates that eThor is practical and outperforms the state-of-the-art static analyzers.
Abstract: Ethereum has emerged as the most popular smart contract development platform, with hundreds of thousands of contracts stored on the blockchain and covering a variety of application scenarios, such as auctions, trading platforms, and so on. Given their financial nature, security vulnerabilities may lead to catastrophic consequences and, even worse, they can be hardly fixed as data stored on the blockchain, including the smart contract code itself, are immutable. An automated security analysis of these contracts is thus of utmost interest, but at the same time technically challenging for a variety of reasons, such as the specific transaction-oriented programming mechanisms, which feature a subtle semantics, and the fact that the blockchain data which the contract under analysis interacts with, including the code of callers and callees, are not statically known.
In this work, we present eThor, the first sound and automated static analyzer for EVM bytecode, which is based on an abstraction of the EVM bytecode semantics based on Horn clauses. In particular, our static analysis supports reachability properties, which we show to be sufficient for capturing interesting security properties for smart contracts (e.g., single-entrancy) as well as contract-specific functional properties. Our analysis is proven sound against a complete semantics of EVM bytecode and an experimental large-scale evaluation on real-world contracts demonstrates that eThor is practical and outperforms the state-of-the-art static analyzers: specifically, eThor is the only one to provide soundness guarantees, terminates on 95% of a representative set of real-world contracts, and achieves an F-measure (which combines sensitivity and specificity) of 89%.
54 citations
Cites background from "A Survey of Attacks on Ethereum Sma..."
...Intuitively, single-entrancy characterizes the robustness of a contract against reentrancy attacks [10, 36]....
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...Furthermore, many smart contracts in the wild are intentionally fraudulent, as highlighted in a recent survey [10]....
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References
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Book•
01 Jan 2002TL;DR: This presentation discusses Functional Programming in HOL, which aims to provide students with an understanding of the programming language through the lens of Haskell.
Abstract: Elementary Techniques.- 1. The Basics.- 2. Functional Programming in HOL.- 3. More Functional Programming.- 4. Presenting Theories.- Logic and Sets.- 5. The Rules of the Game.- 6. Sets, Functions, and Relations.- 7. Inductively Defined Sets.- Advanced Material.- 8. More about Types.- 9. Advanced Simplification, Recursion, and Induction.- 10. Case Study: Verifying a Security Protocol.
2,964 citations
01 Jan 2013
TL;DR: Ethereum as mentioned in this paper is a transactional singleton machine with shared state, which can be seen as a simple application on a decentralised, but singleton, compute resource, and it provides a plurality of resources, each with a distinct state and operating code but able to interact through a message-passing framework with others.
Abstract: The blockchain paradigm when coupled with cryptographically-secured transactions has demonstrated its
utility through a number of projects, not least Bitcoin. Each such project can be seen as a simple application on a decentralised, but singleton, compute resource. We can call this paradigm a transactional singleton machine with shared-state.
Ethereum implements this paradigm in a generalised manner. Furthermore it provides a plurality of such resources, each with a distinct state and operating code but able to interact through a message-passing framework with others. We discuss its design, implementation issues, the opportunities it provides and the future hurdles we envisage.
2,755 citations
TL;DR: Protocols with application in important contracting areas, including credit, content rights management, payment systems, and contracts with bearer are discussed.
Abstract: Smart contracts combine protocols with user interfaces to formalize and secure relationships over computer networks. Objectives and principles for the design of these systems are derived from legal principles, economic theory, and theories of reliable and secure protocols. Similarities and differences between smart contracts and traditional business procedures based on written contracts, controls, and static forms are discussed. By using cryptographic and other security mechanisms, we can secure many algorithmically specifiable relationships from breach by principals, and from eavesdropping or malicious interference by third parties, up to considerations of time, user interface, and completeness of the algorithmic specification. This article discusses protocols with application in important contracting areas, including credit, content rights management, payment systems, and contracts with bearer.
1,495 citations
24 Oct 2016
TL;DR: This paper introduces a novel quantitative framework to analyse the security and performance implications of various consensus and network parameters of PoW blockchains and devise optimal adversarial strategies for double-spending and selfish mining while taking into account real world constraints.
Abstract: Proof of Work (PoW) powered blockchains currently account for more than 90% of the total market capitalization of existing digital cryptocurrencies. Although the security provisions of Bitcoin have been thoroughly analysed, the security guarantees of variant (forked) PoW blockchains (which were instantiated with different parameters) have not received much attention in the literature. This opens the question whether existing security analysis of Bitcoin's PoW applies to other implementations which have been instantiated with different consensus and/or network parameters. In this paper, we introduce a novel quantitative framework to analyse the security and performance implications of various consensus and network parameters of PoW blockchains. Based on our framework, we devise optimal adversarial strategies for double-spending and selfish mining while taking into account real world constraints such as network propagation, different block sizes, block generation intervals, information propagation mechanism, and the impact of eclipse attacks. Our framework therefore allows us to capture existing PoW-based deployments as well as PoW blockchain variants that are instantiated with different parameters, and to objectively compare the tradeoffs between their performance and security provisions.
1,258 citations
24 Oct 2016
TL;DR: This paper investigates the security of running smart contracts based on Ethereum in an open distributed network like those of cryptocurrencies, and proposes ways to enhance the operational semantics of Ethereum to make contracts less vulnerable.
Abstract: Cryptocurrencies record transactions in a decentralized data structure called a blockchain. Two of the most popular cryptocurrencies, Bitcoin and Ethereum, support the feature to encode rules or scripts for processing transactions. This feature has evolved to give practical shape to the ideas of smart contracts, or full-fledged programs that are run on blockchains. Recently, Ethereum's smart contract system has seen steady adoption, supporting tens of thousands of contracts, holding millions dollars worth of virtual coins. In this paper, we investigate the security of running smart contracts based on Ethereum in an open distributed network like those of cryptocurrencies. We introduce several new security problems in which an adversary can manipulate smart contract execution to gain profit. These bugs suggest subtle gaps in the understanding of the distributed semantics of the underlying platform. As a refinement, we propose ways to enhance the operational semantics of Ethereum to make contracts less vulnerable. For developers writing contracts for the existing Ethereum system, we build a symbolic execution tool called Oyente to find potential security bugs. Among 19, 336 existing Ethereum contracts, Oyente flags 8, 833 of them as vulnerable, including the TheDAO bug which led to a 60 million US dollar loss in June 2016. We also discuss the severity of other attacks for several case studies which have source code available and confirm the attacks (which target only our accounts) in the main Ethereum network.
1,232 citations