The platforms supporting the smart city applications are rarely implemented from scratch by a municipality and/or totally owned by a single company, but are more typically realized by integrating some existing ICT infrastructures thanks to a supporting platform, such as the well known FIWARE platform. Such a multi-tenant deployment model is required to lower the initial investment costs to implement large scale solutions for smart cities, but also imposes some key security obstacles. In fact, smart cities support critical applications demanding to protect the data and functionalities from malicious and unauthorized uses. Equipping the supporting platforms with proper means for access control is demanding, but these means are typically implemented according to a centralized approach, where a single server stores and makes available a set of identity attributes and authorization policies. Having a single root of trust is not suitable in a distributed and cooperating scenario of large scale smart cities due to their multi-tenant deployment. In fact, each of the integrated system has its own set of security policies, and the other systems need to be aware of these policy, in order to allow a seamless use of the same credentials across the overall infrastructure (realizing what is known as the single-sign-on). This imposes the problem of consistent and secure data replicas within a distributed system, which can be properly approached by using the blockchain technology. Therefore, this work proposes a novel solution for distributed management of identity and authorization policies by leveraging on the blockchain technology to hold a global view of the security policies within the system, and integrating it in the FIWARE platform. A detailed assessment is provided to evaluate the goodness of the proposed approach and to compare it with the existing solutions.

Blockchain-based authentication and authorization for smart city applications

The industrial Internet of Things (IIoT) supports recent developments in data management and information services, as well as services for smart factories. Nowadays, many mature IIoT cloud platforms are available to serve smart factories. However, due to the semicredibility nature of the IIoT cloud platforms, how to achieve secure storage, access control, information update and deletion for smart factory data, as well as the tracking and revocation of malicious users has become an urgent problem. To solve these problems, in this article, a blockchain-enhanced security access control scheme that supports traceability and revocability has been proposed in IIoT for smart factories. The blockchain first performs unified identity authentication, and stores all public keys, user attribute sets, and revocation list. The system administrator then generates system parameters and issues private keys to users. The domain administrator is responsible for formulating domain security and privacy-protection policies, and performing encryption operations. If the attributes meet the access policies and the user's ID is not in the revocation list, they can obtain the intermediate decryption parameters from the edge/cloud servers. Malicious users can be tracked and revoked during all stages if needed, which ensures the system security under the Decisional Bilinear Diffie–Hellman (DBDH) assumption and can resist multiple attacks. The evaluation has shown that the size of the public/private keys is smaller compared to other schemes, and the overhead time is less for public key generation, data encryption, and data decryption stages.

Blockchain-Enhanced Data Sharing With Traceable and Direct Revocation in IIoT

Big data has generated strong interest in various scientific and engineering domains over the last few years. Despite many advantages and applications, there are many challenges in big data to be tackled for better quality of service, e.g., big data analytics, big data management, and big data privacy and security. Blockchain with its decentralization and security nature has the great potential to improve big data services and applications. In this article, we provide a comprehensive survey on blockchain for big data, focusing on up-to-date approaches, opportunities, and future directions. First, we present a brief overview of blockchain and big data as well as the motivation behind their integration. Next, we survey various blockchain services for big data, including blockchain for secure big data acquisition, data storage, data analytics, and data privacy preservation. Then, we review the state-of-the-art studies on the use of blockchain for big data applications in different vertical domains such as smart city, smart healthcare, smart transportation, and smart grid. For a better understanding, some representative blockchain-big data projects are also presented and analyzed. Finally, challenges and future directions are discussed to further drive research in this promising area.

A Survey on Blockchain for Big Data: Approaches, Opportunities, and Future Directions.

Blockchain has been one of the most attractive technologies for many modern and even future applications. Fabric, an open-source framework to implement the permissioned enterprise-grade blockchain, is getting increasing attention from innovators. The latency performance is crucial to the Fabric blockchain in assessing its effectiveness. Many empirical studies were conducted to analyze this performance based on different hardware platforms. These experimental results are not comparable as they are highly dependent on the underlying networks. Moreover, theoretical analysis on the latency of Fabric blockchain still receives much less attention. This paper provides a novel theoretical model to calculate the transaction latency under various network configurations such as block size, block interval, etc. Subsequently, we validate the proposed latency model with experiments, and the results show that the difference between analytical and experimental results is as low as 6.1 % . We also identify some performance bottlenecks and give insights from the developer’s perspective.

Latency performance modeling and analysis for hyperledger fabric blockchain network

Blockchain is a technology that has desirable features of decentralization, autonomy, integrity, immutability, verification, fault-tolerance, anonymity, auditability, and transparency. In this paper, we first carry out a deeper survey about blockchain technology, especially its history, consensus algorithms' quantitative comparisons, details of cryptography in terms of public key cryptography, Zero-Knowledge Proofs, and hash functions used in the blockchain, and the comprehensive list of blockchain applications. Further, the security of blockchain itself is a focus in this paper. In particular, we assess the blockchain security from risk analysis to derive comprehensive blockchain security risk categories, analyze the real attacks and bugs against blockchain, and summarize the recently developed security measures on blockchain. Finally, the challenges and research trends are presented to achieve more scalable and securer blockchain systems for the massive deployments. 

A Survey on Blockchain Technology and its security

Blockchain technologies have grown in prominence in recent years, with many experts citing the potential applications of the technology in regard to different aspects of any industry, market, agency, or governmental organizations. In the brief history of blockchain, an incredible number of achievements have been made regarding how blockchain can be utilized and the impacts it might have on several industries. The sheer number and complexity of these aspects can make it difficult to address blockchain potentials and complexities, especially when trying to address its purpose and fitness for a specific task. In this survey, we provide a comprehensive review of applying blockchain as a service for applications within today’s information systems. The survey gives the reader a deeper perspective on how blockchain helps to secure and manage today information systems. The survey contains a comprehensive reporting on different instances of blockchain studies and applications proposed by the research community and their respective impacts on blockchain and its use across other applications or scenarios. Some of the most important findings this survey highlights include the fact that blockchain’s structure and modern cloud- and edge-computing paradigms are crucial in enabling a widespread adaption and development of blockchain technologies for new players in today unprecedented vibrant global market. Ensuring that blockchain is widely available through public and open-source code libraries and tools will help to ensure that the full potential of the technology is reached and that further developments can be made concerning the long-term goals of blockchain enthusiasts.

A Survey on Blockchain for Information Systems Management and Security

Blockchain, cryptographically linked blocks of data, is the key technology behind the infamous cryptocurrency Bitcoin, however, blockchain can serve more use cases than just cryptocurrency The technology has use cases in any industry that generates and transfers data In a use case such as cryptocurrency the blockchain is used to manage transactions from peer-to-peer in a way that does not allow for that transaction's data to be manipulated by one of the involved parties or a third party This is a valuable process that other industries could leverage One such industry that could benefit from applying blockchain technology for a multitude of cases is the healthcare industry Primary care doctors could be connected to a blockchain system that allowed them to access patient data and securely monitor the respective patient, pharmaceutical companies could increase their products validity in the marketplace with individual product tracking, and the insurance industry could trust all the information about a client All of these are possible use cases for blockchain in the healthcare industry Currently, the healthcare industry is not leveraging the blockchain at scale Within this paper we are going to explore the possibilities for blockchain technology and the use cases in the healthcare industry specifically, and how the different industries within the healthcare industry can implement a blockchain system

A Survey on Blockchain for Healthcare Informatics and Applications

Artificial intelligence foundation and pre-trained models: Fundamentals, applications, opportunities, and social impacts

Over the years, smartphones have become vital devices for personal, and commercial uses. The number of smartphones has increased dramatically offering many opportunities and yet, challenges. Recently, more attention has been paid for the energy consumed by smartphone applications due to its limited power source (i.e., batteries). Mobile operating systems apply optimizations to power management that are not common with traditional operating systems, and application developers need to consider energy optimization as an important requirement. The need to optimize power consumption has given rise to the development of tools to analyze and identify how and when power is used. In this paper, we present and compare various tools aimed at performing this type of analysis for Android applications.

Identifying Sources of Energy Consumption for Android Applications: A Pilot Study

Edge networking is poised to have a major impact in a number of fields, applications and services. In order to facilitate this, more advanced simulation will be necessary to model modern networked communication standards and develop edge computing frameworks which can take full advantage of the net-work's capabilities. PureEdgeSim is one such simulation system, which supports a high degree of modularity and extensibility. One extension is proposed and implemented here to add support to PureEdgeSim for 5G communication, based on parameter tuning derived from the technical specifications of 5G communication. The proposed extension of 5G communication is compared to the base with regards to task success rate, energy consumption, and network usage, and offers a difference in simulated performance consistent with expected 5G computing implementations. We used a lightweight machine earning applications like workload for experiments.

David Berdik

Papers

A Survey on Blockchain for Information Systems Management and Security

A Survey on Blockchain for Healthcare Informatics and Applications

Artificial intelligence foundation and pre-trained models: Fundamentals, applications, opportunities, and social impacts

Identifying Sources of Energy Consumption for Android Applications: A Pilot Study

Modeling and Simulation of 5G-based Edge Networks for Lightweight Machine Learning Applications