Roberto Saia, Salvatore Carta, Diego Reforgiato Recupero, Gianni Fenu
The exponential growth of wireless-based solutions, such as those related to the mobile smart devices (e.g., smart-phones and tablets) and Internet of Things (IoT) devices, has lead to countless advantages in every area of our society. Such a scenario has transformed the world a few decades back, dominated by latency, into a new world based on an efficient real-time interaction paradigm. Recently, cryptocurrency has contributed to this technological revolution, whose fulcrum is a decentralization model and a certification function offered by the so-called blockchain infrastructure, which makes it possible to certify the financial transactions, anonymously. This paper aims to indicate a possible approach able to exploit this challenging scenario synergistically by introducing a novel blockchain-based distributed paradigm for data exchange between wireless-based devices defined Internet of Entities (IoE). It is based on two core elements with interchangeable roles, entities and trackers, which can be implemented by using existing infrastructures and devices, such as those related to smart-phones, tablets, and IoT systems. The employment of the blockchain-based distributed paradigm allows our approach ensuring the anonymization and immutability of the involved data, which is key in many scenarios and domains (e.g. financial applications, health and legal applications dealing with personal and sensitive data), requirements more and more searched in recent innovations. The possibility to exchange data among a huge number of devices gives rise to a novel and widely exploitable data environment, whose applications are possible in different domains, such as, in Security, eHealth, and Smart Cities.
<p>IoT applications are starting to rely heavily on edge computing due to the advent of low-power and high data-rate wireless communication technologies such as 5G and the processing capability of GPU-driven edge platforms. However, the computation and the data communication model for the edge computing applications are quite diverse, which limits their interoperability. An interoperable edge computing architecture with a versatile communication model would lead to the development of innovative and incentive-driven edge computing applications by combining various data sources from a wide array of devices. In this paper, we present an edge computing architecture by extending the publish-subscribe protocol with support for incentives. Our novel publish-pay-subscribe protocol enables the data producers (publishers) to sell their data with data consumers and service providers (subscribers). The proposed architecture not only allows the device owners to gain incentive but also enable the service providers to sell the processed data with one or more data consumers. Our proof-of-concept implementation using AEDES publish-subscribe broker and Ethereum cryptocurrency shows the feasibility of publish-pay-subscribe broker and its support for data-driven and incentive-based edge computing applications.</p>
In our view the fundamental obstacle to open access (OA) is the lack of any incentive-based mechanism that unbundles authors’ accepted manuscripts (AMs) from articles (VoRs). The former can be seen as the public good that ought to be openly accessible, whereas the latter is owned by publishers and rightly paywall-restricted. We propose one such mechanism to overcome this obstacle: BitViews. BitViews is a blockchain-based application that aims to revolutionize the OA publishing ecosystem. Currently, the main academic currency of value is the citation. There have been attempts in the past to create a second currency whose measure is the online usage of research materials (e.g. PIRUS). However, these have failed due to two problems. Firstly, it has been impossible to find a single agency willing to co-ordinate and fund the validation and collation of global online usage data. Secondly, online usage metrics have lacked transparency in how they filter non-human online activity. BitViews is a novel solution which uses blockchain technology to bypass both problems: online AMS usage will be recorded on a public, distributed ledger, obviating the need for a central responsible agency, and the rules governing activity-filtering will be part of the open-source BitViews blockchain application, creating complete transparency. Once online AMS usage has measurable value, researchers will be incentivized to promote and disseminate AMs. This will fundamentally re-orient the academic publishing ecosystem. A key feature of BitViews is that its success (or failure) is wholly and exclusively in the hands of the worldwide community of university and research libraries, as we suggest that it ought to be financed by conditional crowdfunding, whereby the actual financial commitment of each contributing library depends on the total amount raised. If the financing target is not reached, then all contributions are returned in full and if the target is over-fulfilled, then the surplus is returned pro rata.
Online content delivery has witnessed dramatic growth recently with traffic consuming over half of today’s Internet bandwidth. This escalating demand has motivated content publishers to move outside the traditional solutions of infrastructure-based content delivery networks (CDNs). Instead, many are employing peer-to-peer data transfers to reduce the service cost and avoid bandwidth over-provision to handle peak demands. Unfortunately, the open access work model of this paradigm, which allows anyone to join, introduces several design challenges related to security, efficiency, and peer availability. In this dissertation, we introduce CacheCash, a cryptocurrency-based decentralized content distribution network designed to address these challenges. CacheCash bypasses the centralized approach of CDN companies for one in which end users organically set up new caches in exchange for cryptocurrency tokens. Thus, it enables publishers to hire caches on an as-needed basis, without constraining these parties with long-term business commitments. To address the challenges encountered as the system evolved, we propose a number of protocols and techniques that represent basic building blocks of CacheCash’s design. First, motivated by the observation that conventional security assessment tools do not suit cryptocurrency-based systems, we propose ABC, a threat modeling framework capable of identifying attacker collusion and the new threat vectors that cryptocurrencies introduce. Second, we propose CAPnet, a defense mechanism against cache accounting attacks (i.e., a client pretends to be served allowing a colluding cache to collect rewards without doing any work). CAPnet features a bandwidth expenditure puzzle that clients must solve over the content before caches are given credit, which bounds the effectiveness of this collusion case. Third, to make it feasible to reward caches per data chunk served, we introduce MicroCash, a decentralized probabilistic micropayment scheme that reduces the overhead of processing these small payments. MicroCash implements several novel ideas that make micropayments more suitable for delay-sensitive applications, such as online content delivery. CacheCash combines the previous techniques to produce a novel service-payment exchange protocol that secures the content distribution process. This protocol utilizes gradual content disclosure and partial payment collection to encourage the honest collaborative work between participants. We present a detailed game theoretic analysis showing how to exploit rational financial incentives to address several security threats. This is in addition to various performance optimization mechanisms that promote system efficiency and scalability. Lastly, we evaluate system performance and show that modest machines can serve/retrieve content at a high bitrate with minimal overhead.
Open access
Caching and Content Delivery
Peer-to-Peer Network Technologies
Advanced Steganography and Watermarking Techniques
The goal of this research is to estimate the data propagation time on the Bitcoin network. Using network coordinates, we estimate the communication latency between computers. Such latency estimation contributes future optimization of data propagation. In this research, we report an experiment on computing the network coordinates. In the current Bitcoin network, it is very difficult to acquire internode delay because the network topology is not available. In this study, we calculate the delay based on our topology estimation and describe the effectiveness of the network coordinates using various topology estimation parameters.
Bitcoin is a decentralized cryptocurrency. It is secure as long as majority of the computational resources are with honest miners who follow the Bitcoin protocol. There has been several attacks on Bitcoin mining process in recent years. Selfish mining has been proposed by which miners can get more reward than their fair share. If 33% of the miners are follow the selfish mining strategy, then the Bitcoin system will no longer remain decentralized. We propose a new mining strategy called the Rational Mining, following which only 28% of miners are enough to make Bitcoin decentralized.We analyze the different strategies and show how a miner can choose a strategy to maximize its gain under different parameter selection.
The old mantra of decentralizing the Internet is coming again with fanfare, this time around the blockchain technology hype. We have already seen a technology supposed to change the nature of the Internet: peer-to-peer. The reality is that peer-to-peer naming systems failed, peer-to-peer social networks failed, and yes, peer-to-peer storage failed as well. In this paper, we will review the research on distributed systems in the last few years to identify the limits of open peer-to-peer networks. We will address issues like system complexity, security and frailty, instability and performance. We will show how many of the aforementioned problems also apply to the recent breed of permissionless blockchain networks. The applicability of such systems to mature industrial applications is undermined by the same properties that make them so interesting for a libertarian audience: namely, their openness, their pseudo-anonymity and their unregulated cryptocurrencies. As such, we argue that permissionless blockchain networks are unsuitable to be the substrate for a decentralized Internet. Yet, there is still hope for more decentralization, albeit in a form somewhat limited with respect to the libertarian view of decentralized Internet: in cooperation rather than in competition with the superpowerful datacenters that dominate the world today. This is derived from the recent surge in interest in byzantine fault tolerance and permissioned blockchains, which opens the door to a world where use of trusted third parties is not the only way to arbitrate an ensemble of entities. The ability of establish trust through permissioned blockchains enables to move the control from the datacenters to the edge, truly realizing the promises of edge-centric computing.
Shantanu Kumar Rahut, Razwan Ahmed Tanvir, Sharfi Rahman, Shamim Akhter
In general, peer reviewing is known as an inspection of a work that is completed by one or more qualified people from the same profession and from the relevant field to make the work more error-free, readable, presentable, and adjustable according to the pre-published requirements and also considered as the primary metric for publishing a research paper, accepting research grants, or selecting award nominees. However, many recent publications are pointing to the biasness and mistreatment in the peer-review process. Thus, the scientific community is involved to generate ideas to advance the reviewing process including standardizing procedures and protocols, blind and electronic reviewing, rigorous methods in reviewer selection, rewarding reviewers, providing detailed feedback or checklist to reviewers, etc. In this chapter, the authors propose a decentralized and anonymous scientific peer-reviewing system using blockchain technology. This system will integrate all the above concern issues and eliminate the bias or trust issues interconnected with the peer-reviewing process.
Secure and stable cryptocurrency key management is important in modern cryptocurrency because the keys are the only way to access digital assets. Although many cryptocurrency wallet schemes have been proposed, some application limitations and inherent security risks still exist. In this paper, we propose a novel cryptocurrency wallet management scheme based on Decentralized Multi-Constrained Derangement (DMCD) to store the keys securely and stably in a decentralized network. Serving as the data distribution strategy, DMCD has high data dispersion and a better balance between the rate of storage space utilization and contribution, which can guarantee the security and stability of the key storage and recovery. In our scheme, to cope with the problem that nodes are frequently online and offline in the decentralized network, we employ a Shamir-Kademlia-Neighbor (SKN) redundancy strategy to ensure the high availability of stored key. Meanwhile, for achieving anonymous communication during DMCD data distribution, based on the Kademlia protocol, we change the Client/Server (C/S) mode of Hordes protocol to a decentralized version. All the proposed technologies can ensure that our scheme works well in a decentralized mode. The experiments and evaluations demonstrate that our scheme is efficient, stable, and secure in the decentralized network.
Distributed Ledger Technology (DLT) is promising to become the foundation of many decentralised systems. However, the unbalanced and unregulated network layout contributes to the inefficiency of DLT especially in the Internet of Things (IoT) environments, where nodes connect to only a limited number of peers. The data communication speed globally is unbalanced and does not live up to the constraints of efficient real-time distributed systems. In this paper, we introduce a new communication protocol, which enables nodes to calculate the tradeoff between connecting/disconnecting a peer in a completely decentralised manner. The network layout globally is continuously re-balancing and optimising along with nodes adjusting their peers. This communication protocol weakened the inequality of the communication network. The experiment suggests this communication protocol is stable and efficient.
Derek Leung, Adam Suhl, Yossi Gilad, Nickolai Zeldovich
Decentralized cryptocurrencies rely on participants to keep track of the state of the system in order to verify new transactions. As the number of users and transactions grows, this requirement becomes a significant burden, requiring users to download, verify, and store a large amount of data to participate.
A purely peer-to-peer version of electronic cash would allow online payments to be sent directly from one party to another without going through a financial institution. Digital signatures provide part of the solution, but the main benefits are lost if a trusted third party is still required to prevent double-spending. We propose a solution to the double-spending problem using a peer-to-peer network. The network timestamps transactions by hashing them into an ongoing chain of hash-based proof-of-work, forming a record that cannot be changed without redoing the proof-of-work. The longest chain not only serves as proof of the sequence of events witnessed, but proof that it came from the largest pool of CPU power. As long as a majority of CPU power is controlled by nodes that are not cooperating to attack the network, they'll generate the longest chain and outpace attackers. The network itself requires minimal structure. Messages are broadcast on a best effort basis, and nodes can leave and rejoin the network at will, accepting the longest proof-of-work chain as proof of what happened while they were gone.