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Fog computing complemented cloud computing integration services in the Internet of Things (IoT) and the web of real-time interactivity. Fog offers faster computing and other services facilities sitting close to user applications. However, secure data transfer in the fog is still a challenging issue requiring attention and efficient deployment of a secure data security scheme. We present an Identity Based Encryption (IBE) scheme to secure data security and transmission in fog clouds and IoT ecosystems. We devise and develop a four-level Hierarchical Identity Based Architecture for Fog Computing (HIBAF) data security scheme to enhance data security. We also analyze the system’s performance regarding response time, CPU utilization, run-time encryption-decryption, and key generation time in the fog computing paradigm to an increasing number of users data-loads. Moreover, we evaluate our scheme and compare the outcomes with different cryptography structures to discern our scheme’s effectiveness. Furthermore, we also evaluate secret key updating time, re-encrypted key updating time, and file revoking time by launching DDoS attacks both in the cloud and fog computing environment to compare improvements of HIBAF in the fog computing paradigm. Finally, through this overall evaluation, we have found that the developed HIBAF scheme provides a 33% performance enhancement in a fog environment in terms of data processing, provision, and management compared to the cloud environment.

Legacy industrial control systems (ICSs) are not designed to be exposed to the Internet and linking them to corporate networks has introduced a large number of cyber security vulnerabilities. Due to the distributed nature of ICS devices, a detection-in-depth strategy is required to simultaneously monitor the behaviour of multiple sources of ICS data. While a detection-in-depth method leads to detecting attacks, like flooding attacks in earlier phases before the attacker can reach the end target, most research papers have focused on anomaly detection based on a single source of ICS data. Here, we present a detection-in-depth method for an ICS network. The new method is called automated flooding attack detection (AFAD) which consists of three stages: data acquisition, pre-processing, and a flooding anomaly detector. Data acquisition includes data collection from different sources like programmable logic controller (PLC) logs and network traffic. We then generate NetFlow data to provide light-weight anomaly detection in ICS networks. NetFlow-based analysis has been used as a scalable method for anomaly detection in high-speed networks. It only analyses packet headers, and it is an efficient method for detecting flooding attacks like denial of service attacks, and its performance is not affected by encrypted data. However, it has not been sufficiently studied in industrial control systems. Besides NetFlow data, ICS device logs are a rich source of information that can be used to detect abnormal behaviour. Both NetFlow traffic and log data are processed in our pre-processing stage. The third stage of AFAD is anomaly detection which consists of two parallel machine learning analysis methods, which respectively analyse the behaviours of device logs and NetFlow records. Due to the lack of enough labelled training datasets in most environments, an unsupervised predictor and an unsupervised clustering method are respectively used in the anomaly detection stage. We validated our approach using traffic captured in a factory automation dataset, Modbus dataset, and SWAT dataset. These datasets contain physical and network level normal and abnormal data. The performance of AFAD was compared with single-layer anomaly detection and with other studies. Results showed the high precision of AFAD in detecting flooding attacks.

Fog computing complements cloud computing by removing several limitations, such as delays and network bandwidth. It emerged to support Internet of Things (IoT) applications wherein its computations and tasks are carried out at the network’s edge. Heterogeneous IoT devices interact with different users throughout a network. However, data security is a crucial concern for IoT, fog and cloud network ecosystems. Since the number of anonymous users increases and new identity disclosures occur within the IoTs, it is becoming challenging to grow mesh networks to deliver end to end communications, as the extended IoT networks resemble a mesh architecture. To reinforce data security over IoTs, we deploy a microservice-based blockchain mechanism for fogs, which works as a decentralized client-server network medium (i.e., secured end device-based communication). We implement a blockchain equipped security scheme to be used with a fog-IoT hierarchical tree-based overlay mesh architecture to address and develop the network performance issues. In this study, we consider encryption and decryption delays from IoT and fog-integrated parts to monitor data records and compare them through the developed security scheme. The blocks of a blockchain offer the desired execution results mainly in terms of the algorithmic efficiency, which correlates with the existing algorithms, namely the Advanced Encryption Standard (AES), the Rivest Shamir Adleman (RSA), and the Data Encryption Standard (DES). Our ‘BFIM’ scheme has an enhanced task scheduling capacity and a more efficient throughput than the AES, DES, RSA resource deliverables (i.e., tasks). Our comprehensive performance evaluation implies that the Blockchain-based Fog IoT Microservice (i.e., BFIM) architecture provides a task delivery efficiency of 78.79% (i.e., task deliverable) and a service delivery efficiency of 83.24% (i.e., task scheduling). The ‘BFIM’ also has an overall process delivery efficiency of 75% (i.e., time delay, throughput) in the fog layer, rather than a central cloud layer running the AES, DES, and RSA algorithms.

This article presents a novel concept for a highly accurate and simple two-port vector signal analyzer. A current phase ratio measurement method is defined for one independent external signal with a restriction of the measuring range ±90 or ±180°. The article presents a new way of phase ratio evaluation of two independent external signals with precise phase determination in a wide range from 0° to 360°. The new functional blocks of the analyzer circuit element act as a four-position radio frequency (RF) switcher and an algorithm for phase determination is presented. Practical application and verification of the results achieved are demonstrated by measuring the phase directional radiation pattern of a complex object such as an aircraft fuselage.