BRAINS 2020 special issue: Blockchain research and applications for innovative networks and services

Blockchain and Distributed Ledger Technologies (DLT) have the potential to disrupt all the industrial domains which involve coordination among autonomous resources. This include finance and payments (e.g., Facebook Diem), but also networks (e.g., power grids or telecom networks), computing (e.g., brokering of edge resources), IoT (e.g., supply chain or industry 4.0), or service platforms (e.g., identity management). The purpose of this special issue is to explore the research challenges in Blockchain technologies while highlighting their promising capabilities in providing reliable and secure applications and services. BRAINS conference series is dedicated to these new advances that could make the world of networks and services more secure, while enabling new distributed business models. Among the top ranked papers presented at 2020 international conference BRAINS, four of them are selected and the extended versions of those papers went under extensive reviews and discussions. These four papers were finally selected for publication in this special issue. The authors of these papers were given the time to update their papers based on the review comments and suggestions provided. The selected papers address topics that play a central role in making blockchain a trustworthy and efficient technology by presenting novel theoretical and/or experimentation results. These four selected papers are addressing various timely issues for Blockchain research and applications, so the reader can get a snapshot of important topics in the domain. We have also chosen to mix the research designs, with two research papers mainly based on an extensive simulation work (first and second papers), one research paper relaying on a software implementation used as a testbed to measure the outputs and to validate the proposed approach (third paper), and one comprehensive survey on an emerging field of research leading to propose a taxonomy (fourth paper). The first paper, “Truthful Decentralized Blockchain Oracles” by Cai et al., presents a novel oracle protocol by proposing a peer prediction-based scoring scheme along with non-linear staking rules, aiming at extracting subjective data truthfully. Specifically, an incentive compatible scoring scheme is designed so that voters uniquely maximize their expected score by honest reporting. The voters are rewarded when their report achieves a relatively high score compared to the rest of the voters, as opposed to the existing schemes, where a reward is only given when they agree to the majority. Furthermore, a non-linear stake scaling rule is proposed to discourage Sybil attacks. Detailed simulation results are also presented to show the operation of the proposed oracle protocol and its improvement compared to indicative mechanisms proposed in the existing literature. The second paper, “Simulating Permissionless Blockchains: Distribution Fitting, Tool Support and a Case Study” by Alharby et al., studies frequency distributions for Ethereum smart contract transactions with respect to Gas Limit, Used Gas, Gas Price, and CPU Time. The distribution fitting utilizes Gaussian Mixture Models, correlation analysis, and ensemble regression techniques. The authors use publicly available Ethereum smart contract data, supplemented with experimental data for over 300,000 smart contracts obtained on a testbed. In addition, they extend the BlockSim simulation tool to support the required distributions and use the simulator for a case study in optimizing miner returns through transaction selection strategies in Ethereum under future scenarios. The outcomes demonstrate the impact of selection strategies on miner return, but also demonstrate the sensitivity of the outcomes to chosen distributions and therefore illustrate the importance of using realistic distributions. The third paper, “Veritaa: A Distributed Public Key Infrastructure with Signature Store” by Schaerer et al., introduces a new Distributed Public Key Infrastructure with Integrated Signature Store (DPKISS), named Veritaa, which enables to manage identity claims, document identifiers, and their relationships. This approach is based on Acyclic Block Confirmation Graph (ABCG), a DLT optimized for graph transactions, completed with reputation metrics. Authors have designed and implemented the proposed architecture of Veritaa, created a testbed, and performed several experiments to assess the added value of this proposal. Finally, the fourth paper, “Identity and Access Management Using Distributed Ledger Technology: A Survey” by Ghaffari et al., provides a comprehensive survey on Blockchain-based solutions for identity and access management (IAM). Authors provide a comprehensive overview of the IAM solutions based on their basic components including identity management, authentication, and access control. They highlight how DLT can offer greater confidentiality and integrity for data and access rule, as well as increasing the availability of the system by removing any single point of failure in the whole procedure. Authors survey the emerging approaches in this field of research and provide a taxonomy to categorize and compare them based on their features. Forthcoming research challenges are finally provided. We expect future work in the area of enhancing Blockchain technologies and foster their adoption for more applications and services and to further explore the topics addressed by the selected papers. The guest editors of this special issue wish to acknowledge the excellent work that has been performed by the authors, who submitted papers, and by the reviewers, who have spent a considerable amount of their time providing high-quality reviews. We would also like to extend our thanks to the editorial board of the International Journal of Network Management, in particular to editor-in-chief James Won-Ki Hong and associate editor-in-chief Jérôme François and Lisandro Zambenedetti Granville, for the great opportunity and their support in editing this special issue. Last but not the least, we thank the editorial team of Wiley, for the support offered to the authors. This is to confirm that there are no data available for this editorial paper.