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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Posted Content•
TL;DR: The paper presents a refinement-based approach that was used to create the specification of the Cap9 framework and proves its consistency, as well as discussion of some encountered difficulties during this process.
Abstract: As smart contracts are growing in size and complexity, it becomes harder and harder to ensure their correctness and security. Due to the lack of isolation mechanisms a single mistake or vulnerability in the code can bring the whole system down, and due to this smart contract upgrades can be especially dangerous. Traditional ways to ensure the security of a smart contract, including DSLs, auditing and static analysis, are used before the code is deployed to the blockchain, and thus offer no protection after the deployment. After each upgrade the whole code need to be verified again, which is a difficult and time-consuming process that is prone to errors. To address these issues a security protocol and framework for smart contracts called Cap9 was developed. It provides developers the ability to perform upgrades in a secure and robust manner, and improves isolation and transparency through the use of a low level capability-based security model. We have used Isabelle/HOL to develop a formal specification of the Cap9 framework and prove its consistency. The paper presents a refinement-based approach that we used to create the specification, as well as discussion of some encountered difficulties during this process.
3 citations
Cites background from "A Survey of Attacks on Ethereum Sma..."
...Such flaws can be turned into vulnerabilities and cause a great harm, and there are many examples of such vulnerabilities and attacks that exploit them [2]....
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TL;DR: This paper identifies a list of properties of financial derivatives written in a DSL for blockchain that exclude several security vulnerabilities and develops an infrastructure that provides means to interactively formalize and prove such properties.
3 citations
Cites background from "A Survey of Attacks on Ethereum Sma..."
...A comprehensive taxonomy of vulnerabilities of smart contracts can be found in [16]....
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...Expressing financial derivatives in a specialized DSL may be more precise and less error prone than specifying them in a general purpose smart contracts language [16]....
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Dissertation•
01 Jan 2018
TL;DR: A tool to extract the state from the native storage of a node of the network with the aim of facilitating the statistical study of the dataset is introduced.
Abstract: Blockchains have gathered phenomenal interest due to their potential to disrupt established business models. Ethereum expanded the properties of blockchains to become a platform for the development and implementation of decentralised Applications. We survey the platform and its associated ecosystem and study the data structures that support the protocol, in particular the global state of the network. We also introduce a tool to extract the state from the native storage of a node of the network with the aim to facilitate the statistical study of the dataset.
3 citations
Cites background from "A Survey of Attacks on Ethereum Sma..."
...Academic research is gathering pace and it is so far focused on network/PoW attacks, such as the 51% and eclipse attacks [25] and application bugs: reentrancy, [3] including effort towards formal verification of contracts [35]....
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TL;DR: In this paper , the authors present a perspective of modern technologies for organizing a foundation for special-purpose financing and consider longevity as a model example of the purpose, which is a natural component due to compliance reasons in certain domains, in which the DAO governance model could be reasonably applied.
Abstract: Decentralized autonomous organizations (DAO) launched on a blockchain and governed by a smart contract promises to bring self-organization to a new technological level. Crisis management has no standard decentralized solution within DAO yet. A central authority is a natural component due to compliance reasons in certain domains, for example, special-purpose financing, in which the DAO governance model could be reasonably applied. More generally, a centralized DAO representative could streamline implementing DAO decisions that involve interactions with legacy systems. The article presents a perspective of modern technologies for organizing a foundation for special-purpose financing and considers longevity as a model example of the purpose.
3 citations
TL;DR: An enterprise-level DNS service scheme based on blockchain technology, formed by installing the blockchain service (Ethereum) on multiple servers, which can effectively solve the problem of single point of failure and decompose the attack traffic through load balancing algorithm.
Abstract: Almost every activity on the Internet starts with a DNS query, and 80% of the query requests will hit on the local DNS cache server. As an important network infrastructure, the local DNS solves the DNS request query problem of the intranet users, but also faces many serious threats, such as single point of failure, DNS pollution, and vulnerability to DDoS attacks. In this paper, we propose an enterprise-level DNS service scheme based on blockchain technology. A distributed structure is formed by installing the blockchain service (Ethereum) on multiple servers. Multiple block nodes provide DNS resolution service at the same time, which can effectively solve the problem of single point of failure. Each block node has the domain name verification function. When the domain name information is updated, multiple nodes implement the voting verification through smart contract, which can effectively reduce the DNS pollution. In the case of DDoS attack, multiple nodes can effectively decompose the attack traffic through load balancing algorithm. In addition, blockchain nodes can run consensus algorithm, which means that even if a node is attacked, the DNS service can still run normally.
3 citations
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