SoK: A Taxonomy for Layer-2 Scalability Related Protocols for Cryptocurrencies

Blockchain based systems, in particular cryptocurrencies, face a serious limitation: scalability. This holds, especially, in terms of number of transactions per second. Several alternatives are currently being pursued by both the research and practitioner communities. One venue for exploration is on protocols that do not constantly add transactions on the blockchain and therefore do not consume the blockchain\u27s resources. This is done using off-chain transactions, i.e., protocols that minimize the interaction with the blockchain, also commonly known as Layer-2 approaches. This work relates several existing off-chain channel methods, also known as payment and state channels, channel network constructions methods, and other components as channel and network management protocols, e.g., routing nodes. All these components are crucial to keep the usability of the channel, and are often overlooked. For the best of our knowledge, this work is the first to propose a taxonomy for all the components of the Layer-2. We provide an extensive coverage on the state-of-art protocols available. We also outline their respective approaches, and discuss their advantages and disadvantages

Personal communication services in wireless networks, Journal of Telecommunications and Information Technology, 2005, nr 4

The paper presents modern personal services and new trends observed in evolution of wireless services. The article covers voice and data transmission services offered in mobile networks as well as information services delivered to users over Internet/IP networks. With reference to voice services, selected GSM services based on IN services platform, e.g., the services of flexible scenarios are described. Moreover, the status of VoIP service provided over WLAN is explained. Concerning data transmission services, selected UMTS services are presented as well. Among information services, presentation of wide scope of services offered to mobile users, e.g., messaging, location-based information, transferring text information, unified communications as well as Internet services, e.g., e-commerce, e-shopping, telebanking and micropayments is done. For both, voice and data transmission services, personal services are presented exclusively. Generally, the most attractive services with personal features are selected and described in this paper

Reputation and Reward : Two Sides of the Same Bitcoin

In Mobile Crowd Sensing (MCS), the power of the crowd, jointly with the sensing capabilities of the smartphones they wear, provides a new paradigm for data sensing. Scenarios involving user behavior or those that rely on user mobility are examples where standard sensor networks may not be suitable, and MCS provides an interesting solution. However, including human participation in sensing tasks presents numerous and unique research challenges. In this paper, we analyze three of the most important: user participation, data sensing quality and user anonymity. We tackle the three as a whole, since all of them are strongly correlated. As a result, we present PaySense, a general framework that incentivizes user participation and provides a mechanism to validate the quality of collected data based on the users' reputation. All such features are performed in a privacy-preserving way by using the Bitcoin cryptocurrency. Rather than a theoretical one, our framework has been implemented, and it is ready to be deployed and complement any existint MCS system

Systematizing Decentralization and Privacy: Lessons from 15 Years of Research and Deployments

Decentralized systems are a subset of distributed systems where multiple authorities control different components and no authority is fully trusted by all. This implies that any component in a decentralized system is potentially adversarial. We revise fifteen years of research on decentralization and privacy, and provide an overview of key systems, as well as key insights for designers of future systems. We show that decentralized designs can enhance privacy, integrity, and availability but also require careful trade-offs in terms of system complexity, properties provided, and degree of decentralization. These trade-offs need to be understood and navigated by designers. We argue that a combination of insights from cryptography, distributed systems, and mechanism design, aligned with the development of adequate incentives, are necessary to build scalable and successful privacy-preserving decentralized systems

Blockchain-hosted data access agreements for remote condition monitoring in rail

Advances in sensor technologies, remote authentication, and high bandwidth data networks mean that Remote Condition Monitoring (RCM) systems are now an essential 'Internet of Things' (IoT) resource for the efficient operation of railway infrastructure. However, the full potential of the big data generated by these systems has yet to be realized. RCM data within the industry is typically collected and used in silos, with limited possibility of exploitation across system boundaries. In 2013, the Rail Safety and Standards Board (RSSB), on behalf of the GB Rail industry, established a cross-industry research program, T1010, which aimed to build stronger cooperation between stakeholders and enable sharing of RCM data. Building on the outputs of T1010, this work explores the use of blockchains and smart contracts in the automation, in an auditable and tamper-proof way, of commercial agreements for RCM data transfers in rail. By removing the limitations of paper-based agreements, we aim to enable innovation in shared business processes and stimulate the market for RCM data in rail. Leveraging existing smart contract-based schemes for trading and sharing IoT data over blockchain networks, we identify suitable methods for the enforcement of agreements, and ensure fair cost attribution between stakeholders, without a Trusted Third Party. The outline of a blockchain-based RCM data audit framework is presented, appropriate data access agreements and accounting models are specified in detail, and three permissioned blockchain platforms (Hyperledger Fabric, Sawtooth, and Iroha) have been analysed for their suitability for implementation. Finally, the paper outlines planned future work around validation of the tools based on two industrial use cases: monitoring systems for unattended overhead line equipment and axle bearings

A framework for cascading payment and content exchange within P2P systems

Advances in computing technology and the proliferation of broadband in the home have opened up the Internet to wider use. People like the idea of easy access to information at their fingertips, via their personal networked devices. This has been established by the increased popularity of Peer-to-Peer (P2P) file-sharing networks. P2P is a viable and cost effective model for content distribution. Content producers require modest resources by today's standards to act as distributors of their content and P2P technology can assist in further reducing this cost, thus enabling the development of new business models for content distribution to realise market and user needs. However, many other consequences and challenges are introduced; more notably, the issues of copyright violation, free-riding, the lack of participation incentives and the difficulties associated with the provision of payment services within a decentralised heterogeneous and ad hoc environment. Further issues directly relevant to content exchange also arise such as transaction atomicity, non-repudiation and data persistence. We have developed a framework to address these challenges. The novel Cascading Payment Content Exchange (CasPaCE) framework was designed and developed to incorporate the use of cascading payments to overcome the problem of copyright violation and prevent free-riding in P2P file-sharing networks. By incorporating the use of unique identification, copyright mobility and fair compensation for both producers and distributors in the content distribution value chain, the cascading payments model empowers content producers and enables the creation of new business models. The system allows users to manage their content distribution as well as purchasing activities by mobilising payments and automatically gathering royalties on behalf of the producer. The methodology used to conduct this research involved the use of advances in service-oriented architecture development as well as the use of object-oriented analysis and design techniques. These assisted in the development of an open and flexible framework which facilitates equitable digital content exchange without detracting from the advantages of the P2P domain. A prototype of the CasPaCE framework (developed in Java) demonstrates how peer devices can be connected to form a content exchange environment where both producers and distributors benefit from participating in the system. This prototype was successfully evaluated within the bounds of an E-learning Content Exchange (EIConE) case study, which allows students within a large UK university to exchange digital content for compensation enabling the better use of redundant resources in the university

Money & Trust in Digital Society, Bitcoin and Stablecoins in ML enabled Metaverse Telecollaboration

We present a state of the art and positioning book, about Digital society tools, namely; Web3, Bitcoin, Metaverse, AI/ML, accessibility, safeguarding and telecollaboration. A high level overview of Web3 technologies leads to a description of blockchain, and the Bitcoin network is specifically selected for detailed examination. Suitable components of the extended Bitcoin ecosystem are described in more depth. Other mechanisms for native digital value transfer are described, with a focus on `money'. Metaverse technology is over-viewed, primarily from the perspective of Bitcoin and extended reality. Bitcoin is selected as the best contender for value transfer in metaverses because of it's free and open source nature, and network effect. Challenges and risks of this approach are identified. A cloud deployable virtual machine based technology stack deployment guide with a focus on cybersecurity best practice can be downloaded from GitHub to experiment with the technologies. This deployable lab is designed to inform development of secure value transaction, for small and medium sized companies

Virtual Currencies Bitcoin & What Now After Liberty Reserve, Silk Road, and Mt. Gox?

During 2013, the U.S. Treasury Department evoked the first use of the 2001 Patriot Act to exclude virtual currency provider Liberty Reserve from the U.S. financial system. This article will discuss: the regulation of virtual currencies, cybercrimes and payment systems, darknets, Tor and the “deep web,” Bitcoin; Liberty Reserve, Silk Road, and Mt. Gox. Virtual currencies have quickly become a reality, gaining significant traction in a very short period of time, and are evolving rapidly