Blockchains and Smart Contracts for the Internet of Things
TL;DR: The conclusion is that the blockchain-IoT combination is powerful and can cause significant transformations across several industries, paving the way for new business models and novel, distributed applications.
Abstract: Motivated by the recent explosion of interest around blockchains, we examine whether they make a good fit for the Internet of Things (IoT) sector. Blockchains allow us to have a distributed peer-to-peer network where non-trusting members can interact with each other without a trusted intermediary, in a verifiable manner. We review how this mechanism works and also look into smart contracts—scripts that reside on the blockchain that allow for the automation of multi-step processes. We then move into the IoT domain, and describe how a blockchain-IoT combination: 1) facilitates the sharing of services and resources leading to the creation of a marketplace of services between devices and 2) allows us to automate in a cryptographically verifiable manner several existing, time-consuming workflows. We also point out certain issues that should be considered before the deployment of a blockchain network in an IoT setting: from transactional privacy to the expected value of the digitized assets traded on the network. Wherever applicable, we identify solutions and workarounds. Our conclusion is that the blockchain-IoT combination is powerful and can cause significant transformations across several industries, paving the way for new business models and novel, distributed applications.
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TL;DR: In this article , the authors present a rigorous review of blockchain implementations with the cyber security perception and energy data protections in smart grids, and describe the major security issues of smart grid scenarios that big data and blockchain can solve.
Abstract: The smart grid idea was implemented as a modern interpretation of the traditional power grid to find out the most efficient way to combine renewable energy and storage technologies. Throughout this way, big data and the Internet always provide a revolutionary solution for ensuring that electrical energy linked intelligent grid, also known as the energy Internet. The blockchain has some significant features, making it an applicable technology for smart grid standards to solve the security issues and trust challenges. This study will present a rigorous review of blockchain implementations with the cyber security perception and energy data protections in smart grids. As a result, we describe the major security issues of smart grid scenarios that big data and blockchain can solve. Then, we identify a variety of recent blockchain-based research works published in various literature and discuss security concerns on smart grid systems. We also discuss numerous similar practical designs, experiments, and items that have recently been developed. Finally, we go through some of the most important research problems and possible directions for using blockchain to address smart grid security concerns.
35 citations
Posted Content•
TL;DR: This paper presents a comprehensive survey of smart contracts with a focus on existing applications and challenges they face, and describes how they are being used for a wide range of purposes.
Abstract: A blockchain-based smart contract or a "smart contract" for short, is a computer program intended to digitally facilitate the negotiation or contractual terms directly between users when certain conditions are met. With the advance in blockchain technology, smart contracts are being used to serve a wide range of purposes ranging from self-managed identities on public blockchains to automating business collaboration on permissioned blockchains. In this paper, we present a comprehensive survey of smart contracts with a focus on existing applications and challenges they face.
35 citations
Cites background from "Blockchains and Smart Contracts for..."
...Some of the popular use cases include: banking, Electronic Medical Record (EMR), IoT data management [39]....
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...IoT Blockchain can provide an infrastructure of distributed devices that replicates the data and validates transactions through secure contracts [27, 102, 77, 69, 39]....
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TL;DR: The proposed architecture exploits the key characteristics of the Blockchain technology, such as openness, immutability, traceability, and fault tolerance, to ensure data privacy in IoT scenarios and, thus, provides a secure environment for communication.
Abstract: The exponential growth in the number of connected devices as well as the data produced from these devices call for a secure and efficient access control mechanism that can ensure the privacy of both users and data. Most of the conventional key management mechanisms depend upon a trusted third party like a registration center or key generation center for the generation and management of keys. Trusting a third party has its own ramifications and results in a centralized architecture; therefore, this article addresses these issues by designing a Blockchain-based distributed IoT architecture that uses hash chains for secure key management. The proposed architecture exploits the key characteristics of the Blockchain technology, such as openness, immutability, traceability, and fault tolerance, to ensure data privacy in IoT scenarios and, thus, provides a secure environment for communication. This article also proposes a scheme for secure and efficient key generation and management for mutual authentication between communication entities. The proposed scheme uses a one-way hash chain technique to provide a set of public and private key pairs to the IoT devices that allow the key pairs to verify themselves at any time. Experimental analysis confirms the superior performance of the proposed scheme to the conventional mechanisms.
35 citations
26 Feb 2018
TL;DR: This paper studies the use of Blockchain to strengthen the security of IoT networks through a resilient, decentralized mechanism for the connected home that enhances the network self-defense by safeguarding critical security-related data.
Abstract: Blockchain is a distributed ledger technology that became popular as the foundational block of the Bitcoin cryptocurrency. Over the past few years it has seen a rapid growth, both in terms of research and commercial usage. Due to its decentralized nature and its inherent use of cryptography, Blockchain provides an elegant solution to the Byzantine Generals Problem and is thus a good candidate for use in areas that require a decentralized consensus among untrusted peers, eliminating the need for a central authority. Internet of Things is a technology paradigm where a multitude of small devices, including sensors, actuators and RFID tags, are interconnected via a common communications medium to enable a whole new range of tasks and applications. However, existing IoT installations are often vulnerable and prone to security and privacy concerns. This paper studies the use of Blockchain to strengthen the security of IoT networks through a resilient, decentralized mechanism for the connected home that enhances the network self-defense by safeguarding critical security-related data. This mechanism is developed as part of the Safe-Guarding Home IoT Environments with Personalised Real-time Risk Control (GHOST) project.
35 citations
Cites methods from "Blockchains and Smart Contracts for..."
...The use of Blockchain technology in the IoT domain to facilitate the sharing of services and resources, and automate in a secure manner several time-consuming workflows, is studied in [2]....
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TL;DR: This article demonstrates the implementation of a real-world blockchain managed microgrid in Walenstadt, Switzerland, and provides simplified guidelines for utilities or grid operators interested in implementing local P2P markets based on BFT systems.
35 citations
Cites background from "Blockchains and Smart Contracts for..."
...A common property of all blockchains is that data is handled in blocks, which are chained after one another, and linked by the data hash of the previous block [11]....
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References
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TL;DR: The Albanian Generals Problem as mentioned in this paper is a generalization of Dijkstra's dining philosophers problem, where two generals have to come to a common agreement on whether to attack or retreat, but can communicate only by sending messengers who might never arrive.
Abstract: I have long felt that, because it was posed as a cute problem about philosophers seated around a table, Dijkstra’s dining philosopher’s problem received much more attention than it deserves. (For example, it has probably received more attention in the theory community than the readers/writers problem, which illustrates the same principles and has much more practical importance.) I believed that the problem introduced in [41] was very important and deserved the attention of computer scientists. The popularity of the dining philosophers problem taught me that the best way to attract attention to a problem is to present it in terms of a story. There is a problem in distributed computing that is sometimes called the Chinese Generals Problem, in which two generals have to come to a common agreement on whether to attack or retreat, but can communicate only by sending messengers who might never arrive. I stole the idea of the generals and posed the problem in terms of a group of generals, some of whom may be traitors, who have to reach a common decision. I wanted to assign the generals a nationality that would not offend any readers. At the time, Albania was a completely closed society, and I felt it unlikely that there would be any Albanians around to object, so the original title of this paper was The Albanian Generals Problem. Jack Goldberg was smart enough to realize that there were Albanians in the world outside Albania, and Albania might not always be a black hole, so he suggested that I find another name. The obviously more appropriate Byzantine generals then occurred to me. The main reason for writing this paper was to assign the new name to the problem. But a new paper needed new results as well. I came up with a simpler way to describe the general 3n+1-processor algorithm. (Shostak’s 4-processor algorithm was subtle but easy to understand; Pease’s generalization was a remarkable tour de force.) We also added a generalization to networks that were not completely connected. (I don’t remember whose work that was.) I also added some discussion of practical implementation details.
5,208 citations
TL;DR: In this article, a group of generals of the Byzantine army camped with their troops around an enemy city are shown to agree upon a common battle plan using only oral messages, if and only if more than two-thirds of the generals are loyal; so a single traitor can confound two loyal generals.
Abstract: Reliable computer systems must handle malfunctioning components that give conflicting information to different parts of the system. This situation can be expressed abstractly in terms of a group of generals of the Byzantine army camped with their troops around an enemy city. Communicating only by messenger, the generals must agree upon a common battle plan. However, one or more of them may be traitors who will try to confuse the others. The problem is to find an algorithm to ensure that the loyal generals will reach agreement. It is shown that, using only oral messages, this problem is solvable if and only if more than two-thirds of the generals are loyal; so a single traitor can confound two loyal generals. With unforgeable written messages, the problem is solvable for any number of generals and possible traitors. Applications of the solutions to reliable computer systems are then discussed.
4,901 citations
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TL;DR: It is shown that, without a logically centralized authority, Sybil attacks are always possible except under extreme and unrealistic assumptions of resource parity and coordination among entities.
Abstract: Large-scale peer-to-peer systems face security threats from faulty or hostile remote computing elements. To resist these threats, many such systems employ redundancy. However, if a single faulty entity can present multiple identities, it can control a substantial fraction of the system, thereby undermining this redundancy. One approach to preventing these "Sybil attacks" is to have a trusted agency certify identities. This paper shows that, without a logically centralized authority, Sybil attacks are always possible except under extreme and unrealistic assumptions of resource parity and coordination among entities.
4,816 citations
"Blockchains and Smart Contracts for..." refers background in this paper
...Because of the Sybil attack [15], consensus in public networks is costly...
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...anyone can join though, this would be catastrophic because of the Sybil attack [15]: a single entity could join with multiple identities, get multiple votes, and thus influence the network to favor this entity’s interests....
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22 Feb 1999
TL;DR: A new replication algorithm that is able to tolerate Byzantine faults that works in asynchronous environments like the Internet and incorporates several important optimizations that improve the response time of previous algorithms by more than an order of magnitude.
Abstract: This paper describes a new replication algorithm that is able to tolerate Byzantine faults. We believe that Byzantinefault-tolerant algorithms will be increasingly important in the future because malicious attacks and software errors are increasingly common and can cause faulty nodes to exhibit arbitrary behavior. Whereas previous algorithms assumed a synchronous system or were too slow to be used in practice, the algorithm described in this paper is practical: it works in asynchronous environments like the Internet and incorporates several important optimizations that improve the response time of previous algorithms by more than an order of magnitude. We implemented a Byzantine-fault-tolerant NFS service using our algorithm and measured its performance. The results show that our service is only 3% slower than a standard unreplicated NFS.
3,562 citations
"Blockchains and Smart Contracts for..." refers background or methods in this paper
...5If more than 3f + 1 nodes are used, then the quorum thresholds listed in [26] may lead to forks....
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...Tendermint vs PBFT—Tendermint....
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...Sieve [38], a mechanism used in the HyperLedger Fabric project, augments the PBFT algorithm [26] by adding speculative execution and verification phases, inspired by the execute-verify architecture presented in [39]....
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...Tendermint [32] provides BFT tolerance and is similar to the PBFT algorithm; however it provides a tighter guarantee with regards to the results returned to the client when more than one third of the nodes are faulty, and allows for a dynamically changing set of set of validators, and leaders that can be rotated in a round-robin manner, among other optimizations [33]....
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...PBFT works on the assumption that less than one third of the nodes are faulty (f ), which is why say that it requires at least5 3f + 1 nodes....
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Proceedings Article•
19 Jun 2014TL;DR: Raft is a consensus algorithm for managing a replicated log that separates the key elements of consensus, such as leader election, log replication, and safety, and it enforces a stronger degree of coherency to reduce the number of states that must be considered.
Abstract: Raft is a consensus algorithm for managing a replicated log. It produces a result equivalent to (multi-)Paxos, and it is as efficient as Paxos, but its structure is different from Paxos; this makes Raft more understandable than Paxos and also provides a better foundation for building practical systems. In order to enhance understandability, Raft separates the key elements of consensus, such as leader election, log replication, and safety, and it enforces a stronger degree of coherency to reduce the number of states that must be considered. Results from a user study demonstrate that Raft is easier for students to learn than Paxos. Raft also includes a new mechanism for changing the cluster membership, which uses overlapping majorities to guarantee safety.
1,811 citations
"Blockchains and Smart Contracts for..." refers methods in this paper
...popular Raft algorithm [30], is used as a consensus mechanism in Juno [31]....
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