Quantum Computers (QCs), once they mature, will be able to solve some problems faster than Classic Computers. This phenomenon is called "quantum advantage" (or a stronger term "quantum supremacy"). Quantum advantage will help us to speed up computations in many areas, from artificial intelligence to medicine. However, QC power can also be leveraged to break modern cryptographic algorithms, which pervade modern software: use cases range from encryption of Internet traffic, to encryption of disks, to signing blockchain ledgers. While the exact date when QCs will evolve to reach quantum advantage is unknown, the consensus is that this future is near. Thus, in order to maintain crypto agility of the software, one needs to start preparing for the era of quantum advantage proactively. In this paper, we recap the effect of quantum advantage on the existing and new software systems, as well as the data that we currently store. We also highlight similarities and differences between the security challenges brought by QCs and the challenges that software engineers faced twenty years ago while fixing widespread Y2K bug. Technically, the Y2K bug and the quantum advantage problems are different: the former was caused by timing-related problems, while the latter is caused by a cryptographic algorithm being non-quantum-resistant. However, conceptually, the problems are similar: we know what the root cause is, the fix (strategically) is straightforward, yet the implementation of the fix is challenging. To address the quantum advantage challenge, we create a seven-step roadmap, deemed 7E. It is inspired by the lessons-learnt from the Y2K era amalgamated with modern knowledge. The roadmap gives developers a structured way to start preparing for the quantum advantage era, helping them to start planning for the creation of new as well as the evolution of the existent software.
John Augustine, Valerie King, Anisur R. Molla, Gopal Pandurangan · 5 authors
Motivated, in part, by the rise of permissionless systems such as Bitcoin where arbitrary nodes (whose identities are not known apriori) can join and leave at will, we extend established research in scalable Byzantine agreement to a more practical model where each node (initially) does not know the identity of other nodes. A node can send to new destinations only by sending to random (or arbitrary) nodes, or responding (if it chooses) to messages received from those destinations. We assume a synchronous and fully-connected network, with a full-information, but static Byzantine adversary. A general drawback of existing Byzantine protocols is that the communication cost incurred by the honest nodes may not be proportional to those incurred by the Byzantine nodes; in fact, they can be significantly higher. Our goal is to design Byzantine protocols for fundamental problems which are {\em resource competitive}, i.e., the number of bits sent by honest nodes is not much more than those sent by Byzantine nodes. We describe a randomized scalable algorithm to solve Byzantine agreement, leader election, and committee election in this model. Our algorithm sends an expected $O((T+n)\log n)$ bits and has latency $O(polylog(n))$, where $n$ is the number of nodes, and $T$ is the minimum of $n^2$ and the number of bits sent by adversarially controlled nodes. The algorithm is resilient to $(1/4-ε)n$ Byzantine nodes for any fixed $ε> 0$, and succeeds with high probability. Our work can be considered as a first application of resource-competitive analysis to fundamental Byzantine problems. To complement our algorithm we also show lower bounds for resource-competitive Byzantine agreement. We prove that, in general, one cannot hope to design Byzantine protocols that have communication cost that is significantly smaller than the cost of the Byzantine adversary.
Bitcoin paper, published under a pseudonym Satoshi Nakamoto, opened a new era; cryptocurrencies, blockchain and distributed ledger technologies that are aiming distributed trust model. Even if there has been an ongoing extensive discussion both on the origin and the future about these developing technologies, number of products, studies and projects are increasing day by day. Among these the most crucial one is crypto wallets since the distributed trust and privacy preserving solutions are all relies on the underlying cryptographic primitives and the corresponding cryptographic keys. Almost all the cryptocurrencies require their users individually manage their own cryptographic keys or recommend use of cryptocurrency wallets. A cryptocurrency wallet or shortly, crypto wallet, has to generate and store one or more public-private keys and corresponding addresses. These keys authenticate corresponding transactions, hence any adversary who gains access to a wallet may seize all the assets secured with them. Therefore, cryptocurrency wallet solutions and products should be carefully analyzed and better to be certified if possible from the very beginning. \nIn this thesis, we mainly focus on to what extend and how a cryptocurrency wallet’s security analysis should be pursued. In order to formally portray the analysis framework, we propose to follow the Common Criteria (CC) Evaluation framework. CC evaluation framework is a formal evaluation methodology. For this purpose, assumptions, risks, threatsandsecurityvulnerabilitiesofthewalletswillbedefined. Also,objectivesshowing howthesethreatswillbecounteredinsidethewalletandwhatkindofmeasuresshouldbe taken by the environment and users will be detailed. In order to understand the security requirements, blockchain technology and Bitcoin which is the leading cryptocurrency will be explained and cryptocurrency wallets will be classified. In addition, we are going to propose a secure hardware wallet design in terms of physical and logical requirements. Then, we will compare the proposed wallet with other hardware wallets on the market. WebelievethatthisthesismaybebasicresourceforcreatingstandardizedCCdocuments such as Protection Profile(PP), Security Target(ST) etc. Furthermore, this study would be a brief source for cryptocurrency wallets’ design, test and analysis phases.
Identity management (IdM) is a method used to determine user identities. The centralized aspect of IdM introduces a serious concern with the growing value of personal information, as well as with the General Data Protection Regulation (GDPR). The problem with currently-deployed systems and their dominating approach, with identity providers (IdP) and single-point services, is that a third party is in charge of maintaining and controlling the personal data. The main challenge to manage data securely lies in trusting humans and institutes who are responsible for controlling the entire activity. Identities are not owned by the rightful owners or the user him/herself, but by the mentioned providers. With the rise of blockchain technology, self-sovereign identities are in place utilizing decentralization; unfortunately, the flaws still exist. In this research, we propose DNS-IdM, a smart contract-based identity management system that enables users to maintain their identities associated with certain attributes, accomplishing the self-sovereign concept. DNS-IdM has promising outcomes in terms of security and privacy. Due to the decentralized nature, DNS-IdM is able to avoid not only the conventional security threats, but also the limitations of the current decentralized identity management systems.
We propose a novel way of embedding functional smart contract languages into the Coq proof assistant using meta-programming techniques. Our framework allows for developing the meta-theory of smart contract languages using the deep embedding and provides a convenient way for reasoning about concrete contracts using the shallow embedding. The proposed approach allows to make a connection between the two embeddings in a form of a soundness theorem. As an instance of our approach we develop an embedding of the Oak smart contract language in Coq and verify several important properties of a crowdfunding contract. The developed techniques are applicable to all functional smart contract languages.
Distributed ledger technology, also known as the blockchain, is gaining traction globally. Blockchain offers a secure validation mechanism and decentralized mass collaboration. Cryptocurrencies make use of this technology as a new asset class for investors worldwide. Cryptocurrencies are being used by companies to raise capital via initial coin offerings (ICOs). The substantial inflow of unregulated capital into a transactional and transnational industry has aroused interest from not just investors, but also national securities and monetary regulatory agencies. In this paper, we review the Security and Exchange Commission’s initial statements and subsequent pronouncements on ICO’s to illustrate the potential problems with applying an older legal framework to an ever-evolving ecosystem. Recognizing the inability of enforcement within existing regulatory frameworks, we discuss the importance of regulation of the crypto asset class and internal collaboration between government agencies and developers in the establishment of an ecosystem that integrates investor protection and investments.
Personal Health Records (PHRs) have the potential to give patients fine-grained, personalized and secure access to their own medical data and to enable self-management of care. Emergent trends around the use of Blockchain, or Distributed Ledger Technology, seem to offer solutions to some of the problems faced in enabling these technologies, especially to support issues consent, data exchange, and data access. We present an analysis of existing blockchain-based health record solutions and a reference architecture for a "Ledger of Me" system that extends PHR to create a new platform combining the collection and access of medical data and digital interventions with smart contracts. Our intention is to enable patient use of the data in order to support their care and to provide a strong consent mechanisms for sharing of data between different organizations and apps. Ledger of Me is based on around the principle that this combination of event-driven smart contracts, medical record data, and patient control is important for the adoption of blockchain-based solutions for the PHR. The reference architecture we present can serve as the basis of a range of future blockchain-based medical application architectures.
Zcash is a privacy-preserving cryptocurrency that provides anonymous monetary transactions. While Zcash's anonymity is part of a rigorous scientific discussion, information on the underlying peer-to-peer network are missing. In this paper, we provide the first long-term measurement study of the Zcash network to capture key metrics such as the network size and node distribution as well as deeper insights on the centralization of the network. Furthermore, we present an inference method based on a timing analysis of block arrivals that we use to determine interconnections of nodes. We evaluate and verify our method through simulations and real-world experiments, yielding a precision of 50 % with a recall of 82 % in the real-world scenario. By adjusting the parameters, the topology inference model is adaptable to the conditions found in other cryptocurrencies and therefore also contributes to the broader discussion of topology hiding in general.
The increasing interest in blockchain since the end of 2017 has induced many attempts to apply it to public sector administration. Blockchains have been shown to improve the levels of economic efficiency, security and decentralization in administration. This exploratory study examines the determinants of blockchain administration and their priorities through an analytic-hierarchy process (AHP) analysis. The priority ranking of internal factors was security, economic efficiency, and decentralization. The introduction of blockchains in the evolution of the current e-government to the future of convergent governments will be generalized through trial, error, and learning processes. As experienced both in the knowledge and information society and in the e-government development process, reforming government administration is not solely a technical problem. The study results suggest that future blockchain administration in the public sector be used in the field of e-voting to encourage citizen participation in the process of agenda-setting, to enhance the level of security and transparency of taxation, and to increase the level of equity. Blockchain technology can also be used to improve efficiency in the provision of individually oriented social welfare services. Its adoption via administrative reform may reduce the level of corruption in personnel management, recruitment, and procurement in public sector organizations.
The recent development in IoT and 5G translates into a significant growth of Big data in 5G—envisioned industrial automation. To support big data analysis, Deep Learning (DL) has been considered the most promising approach in recent years. Note, however, that designing an effective DL paradigm for IoT has certain challenges such as single point of failure, privacy leak of IoT devices, lack of valuable data for DL, and data poisoning attacks. To this end, we present BlockDeepNet, a Blockchain-based secure DL that combines DL and blockchain to support secure collaborative DL in IoT. In BlockDeepNet, collaborative DL is performed at the device level to overcome privacy leak and obtain enough data for DL, whereas blockchain is employed to ensure the confidentiality and integrity of collaborative DL in IoT. The experimental evaluation shows that BlockDeepNet can achieve higher accuracy for DL with acceptable latency and computational overhead of blockchain operation.
Fengkie Junis, Faisal Malik Widya Prasetya, Farouq Ibrahim Lubay, Anny Kartika Sari
Blockchain-based smart contract has become a growing field in the blockchain technology. What was once a technology used to solve digital transaction issues turns out to have some wider usage, including smart contract. The development of smart contract can be traced from the numerous platforms facilitating it, however the issue on how well each platform works as oppose to each other has yet been fully explored. The usage of smart contract can be seen from the applications that are built on top of the smart contract platform, such as the tokenization of real world to virtual world assets. However smart contract contains several issues concerning security and codifying which could be solved by various tools that are proposed by existing research. This paper aims to revisit the blockchain-based smart contract technology in order to understand and discuss the research gaps gathered from existing research and to provide guidance for future research.
Open access
2 source records
Blockchain Technology Applications and Security
FinTech, Crowdfunding, Digital Finance
Advanced Steganography and Watermarking Techniques
The Ethereum blockchain is essentially a globally replicated public database.\nPrograms called smart contracts can access this database. Over 10 million smart\ncontracts have been deployed on the Ethereum blockchain. Executing a method of\na smart contract generates a transaction that is also stored on the blockchain.\nThere are over 1 billion Ethereum transactions to date. Smart contracts that\nare transparent about their function are more successful than opaque contracts.\nWe have therefore developed a tool (ContractVis) to explore the transparency of\nsmart contracts. The tool generates a replay script for the historic\ntransactions of a smart contract. The script executes the transactions with the\nsame arguments as recorded on the blockchain, but in a minimal test\nenvironment. Running a replay script provides insights into the contract, and\ninsights into the blockchain explorer that was used to retrieve the contract\nand its history. We provide five concrete recommendations for blockchain\nexplorers like Etherscan to improve the transparency of smart contracts.\n
Open access
3 source records
Blockchain Technology Applications and Security
Auction Theory and Applications
Advanced Steganography and Watermarking Techniques
Blockchain has been emerging as a promising technology that could totally change the landscape of data security in the coming years, particularly for data access over Internet-of-Things and cloud servers. However, blockchain itself, though secured by its protocol, does not identify who owns the data and who uses the data. Other than simply encrypting data into keys, in this paper, we proposed a protocol called Biometric Blockchain (BBC) that explicitly incorporate the biometric cues of individuals to unambiguously identify the creators and users in a blockchain-based system, particularly to address the increasing needs to secure the food logistics, following the recently widely reported incident on wrongly labelled foods that caused the death of a customer on a flight. The advantage of using BBC in the food logistics is clear: it can not only identify if the data or labels are authentic, but also clearly record who is responsible for the secured data or labels. As a result, such a BBC-based solution can great ease the difficulty to control the risks accompanying the food logistics, such as faked foods or wrong gradient labels.
Audit logs serve as a critical component in enterprise business systems and are used for auditing, storing, and tracking changes made to the data. However, audit logs are vulnerable to a series of attacks enabling adversaries to tamper data and corresponding audit logs without getting detected. Among them, two well-known attacks are "the physical access attack," which exploits root privileges, and "the remote vulnerability attack," which compromises known vulnerabilities in database systems. In this paper, we present BlockAudit: a scalable and tamper-proof system that leverages the design properties of audit logs and security guarantees of blockchain to enable secure and trustworthy audit logs. Towards that, we construct the design schema of BlockAudit and outline its functional and operational procedures. We implement our design on a custom-built Practical Byzantine Fault Tolerance (PBFT) blockchain system and evaluate the performance in terms of latency, network size, payload size, and transaction rate. Our results show that conventional audit logs can seamlessly transition into BlockAudit to achieve higher security and defend against the known attacks on audit logs.
Biological cells can transmit, process and receive chemically encoded data in the same way as network devices transmit, process, and receive digitally encoded data. Communication protocols have led to the rapid development of computer networks. Therefore, we need to develop communication protocols for biological cell networks, which will lead to significant development, especially in medical applications where surgery or delivery of drugs can be performed using nanoscale devices. Blockchain is a peer-to-peer network that contains a series of clusters to make a valid and secure transaction. Blockhain technology is used in many areas such as e-commerce, public services, security, finance, Internet stuff, etc. Although blockchain has a major impact on Internet technology, it suffers from time problems and scalability. DNA computing is the execution of computations using natural molecules, especially DNA. DNA gaps above silicon because of massive parallelism, size and storage density. In this paper, biological cells and DNA are used to create the necessary protocols for the networks to be used in the performance of the cell-based communication system. The proposed hybrid solution involves DNA as well as calculated on an enzymatic basis, where each contributes to the function of a given protocol. Also a correspondence between blockchain and DNA is proposed that can be utilized to create DNA based blockchain.
Shivam Saxena, Hany E. Z. Farag, Aidan Brookson, Hjalmar Turesson · 5 authors
This paper proposes a peer to peer (P2P), blockchain based energy trading market platform for residential communities with the objective of reducing overall community peak demand and household electricity bills. Smart homes within the community place energy bids for its available distributed energy resources (DERs) for each discrete trading period during a day, and a double auction mechanism is used to clear the market and compute the market clearing price (MCP). The marketplace is implemented on a permissioned blockchain infrastructure, where bids are stored to the immutable ledger and smart contracts are used to implement the MCP calculation and award service contracts to all winning bids. Utilizing the blockchain obviates the need for a trusted, centralized auctioneer, and eliminates vulnerability to a single point of failure. Simulation results show that the platform enables a community peak demand reduction of 46%, as well as a weekly savings of 6%. The platform is also tested at a real-world Canadian microgrid using the Hyperledger Fabric blockchain framework, to show the end to end connectivity of smart home DERs to the platform.
Hjalmar Turesson, Henry M. Kim, Marek Laskowski, Alexandra Roatis
Blockchains rely on a consensus among participants to achieve decentralization and security. However, reaching consensus in an online, digital world where identities are not tied to physical users is a challenging problem. Proof-of-work provides a solution by linking representation to a valuable, physical resource. While this has worked well, it uses a tremendous amount of specialized hardware and energy, with no utility beyond blockchain security. Here, we propose an alternative consensus scheme that directs the computational resources to the optimization of machine learning (ML) models, a task with more general utility. This is achieved by a hybrid consensus scheme relying on three parties: data providers, miners, and a committee. The data provider makes data available and provides payment in return for the best model, miners compete about the payment and access to the committee by producing ML optimized models, and the committee controls the ML competition.
Abderahman Rejeb, John G. Keogh, Horst Treiblmaier
Modern supply chains have evolved into highly complex value networks and turned into a vital source of competitive advantage. However, it has become increasingly challenging to verify the source of raw materials and maintain visibility of products and merchandise while they are moving through the value chain network. The application of the Internet of Things (IoT) can help companies to observe, track, and monitor products, activities, and processes within their respective value chain networks. Other applications of IoT include product monitoring to optimize operations in warehousing‚ manufacturing, and transportation. In combination with IoT, Blockchain technology can enable a broad range of different application scenarios to enhance value chain transparency and to increase B2B trust. When combined, IoT and Blockchain technology have the potential to increase the effectiveness and efficiency of modern supply chains. The contribution of this paper is twofold. First, we illustrate how the deployment of Blockchain technology in combination with IoT infrastructure can streamline and benefit modern supply chains and enhance value chain networks. Second, we derive six research propositions outlining how Blockchain technology can impact key features of the IoT (i.e., scalability, security, immutability and auditing, information flows, traceability and interoperability, quality) and thus lay the foundation for future research projects.
Shivam Saxena, Hany Farag, Hjalmar Turesson, Henry M. Kim
Transactive Energy Systems (TES) are modern mechanisms in electric power systems that allow disparate control agents to utilize distributed generation units (DGs) to engage in energy transactions and provide ancillary services to the grid. Although voltage regulation is a crucial ancillary service within active distribution networks (ADNs), previous work has not adequately explored how this service can be offered in terms of its incentivization, contract auditability and enforcement. Blockchain technology shows promise in being a key enabler of TES, allowing agents to engage in trustless, persistent transactions that are both enforceable and auditable. To that end, this paper proposes a blockchain based TES that enables agents to receive incentives for providing voltage regulation services by i) maintaining an auditable reputation rating for each agent that is increased proportionately with each mitigation of a voltage violation, ii) utilizing smart contracts to enforce the validity of each transaction and penalize reputation ratings in case of a mitigation failure and iii) automating the negotiation and bidding of agent services by implementing the contract net protocol (CNP) as a smart contract. Experimental results on both simulated and real-world ADNs are executed to demonstrate the efficacy of the proposed system.