A Numerical Approach for Assigning a Reputation to Users of an IoT Framework

AbstractNowadays, in the Internet of Things (IoT) society, the massive use of technological devices available to the people makes possible to collect a lot of data describing tastes, choices and behaviours related to the users of services and tools. These information can be rearranged and interpreted in order to obtain a rating (i.e., evaluation) of the subjects (i.e., users) interacting with specific objects (i.e., items). Generally, reputation systems are widely used to provide ratings to products, services, companies, digital contents and people. Here, we focus on this issue, adopting a Collaborative Reputation System (CRS) to evaluate the visitors' behaviour in a real cultural event. The results obtained, compared with those obtained by other methods (i.e., classification), have confirmed the reliability and the usefulness of CRSes for deeply understand dynamics related to visiting styles

Data Aggregation Technique to Provide Security for Wireless Sensor Networks

Due to restricted computational power and energy assets, the aggregation of information from numerous sensor nodes is performed at the aggregating node and is typically done by using basic techniques, for example by averaging. Node compromising attacks more likely occur after such sort of aggregations of data. As wireless sensor networks are generally unattended and do not use any tamper resistant equipment, they are extremely vulnerable to compromising attacks. Therefore, determining the trustworthiness of information and the reputation of sensor hubs is vital for wireless sensor networks. As the execution of low power processors drastically enhances, future aggregator nodes will be equipped for performing more refined information aggregation algorithms, in this way making WSN less vulnerable. WSN stands for Wireless Sensor Networks. For this reason, Iterative algorithms hold high value. These algorithms take the data aggregated from different sources and give a trust appraisal of these sources, generally in the form of comparing weight variables which are given to information obtained from every source. In this paper, we show that few existing iterative filtering calculations, while altogether more vigorous against collusion attacks than the basic averaging methods, are in fact susceptive to a novel refined collusion attack which we launch. To address this security issue, we propose a change for iterative filtering procedures by giving an underlying estimation to such algorithms which make them collusion resistant as well as more precise and faster for merging purposes

Improving IF Algorithm for Data Aggregation Techniques in Wireless Sensor Networks

In Wireless Sensor Network (WSN), fact from different sensor nodes is collected at assembling node, which is typically complete via modest procedures such as averaging as inadequate computational power and energy resources. Though such collections is identified to be extremely susceptible to node compromising attacks. These approaches are extremely prone to attacks as WSN are typically lacking interfere resilient hardware. Thus, purpose of veracity of facts and prestige of sensor nodes is critical for wireless sensor networks. Therefore, imminent gatherer nodes will be proficient of accomplishment additional cultivated data aggregation algorithms, so creating WSN little unresisting, as the performance of actual low power processors affectedly increases. Iterative filtering algorithms embrace inordinate capacity for such a resolution. The way of allocated the matching mass elements to information delivered by each source, such iterative algorithms concurrently assemble facts from several roots and deliver entrust valuation of these roots. Though suggestively extra substantial against collusion attacks beside the modest averaging techniques, are quiet vulnerable to a different cultivated attack familiarize. The existing literature is surveyed in this paper to have a study of iterative filtering techniques and a detailed comparison is provided. At the end of this paper new technique of improved iterative filtering is proposed with the help of literature survey and drawbacks found in the literature

A Framework of Algorithms: Computing the Bias and Prestige of Nodes in Trust Networks

A trust network is a social network in which edges represent the trust relationship between two nodes in the network. In a trust network, a fundamental question is how to assess and compute the bias and prestige of the nodes, where the bias of a node measures the trustworthiness of a node and the prestige of a node measures the importance of the node. The larger bias of a node implies the lower trustworthiness of the node, and the larger prestige of a node implies the higher importance of the node. In this paper, we define a vector-valued contractive function to characterize the bias vector which results in a rich family of bias measurements, and we propose a framework of algorithms for computing the bias and prestige of nodes in trust networks. Based on our framework, we develop four algorithms that can calculate the bias and prestige of nodes effectively and robustly. The time and space complexities of all our algorithms are linear w.r.t. the size of the graph, thus our algorithms are scalable to handle large datasets. We evaluate our algorithms using five real datasets. The experimental results demonstrate the effectiveness, robustness, and scalability of our algorithms

Robust reputation independence in ranking systems for multiple sensitive attributes

Ranking systems have an unprecedented influence on how and what information people access, and their impact on our society is being analyzed from different perspectives, such as users’ discrimination. A notable example is represented by reputation-based ranking systems, a class of systems that rely on users’ reputation to generate a non-personalized item-ranking, proved to be biased against certain demographic classes. To safeguard that a given sensitive user’s attribute does not systematically affect the reputation of that user, prior work has operationalized a reputation independence constraint on this class of systems. In this paper, we uncover that guaranteeing reputation independence for a single sensitive attribute is not enough. When mitigating biases based on one sensitive attribute (e.g., gender), the final ranking might still be biased against certain demographic groups formed based on another attribute (e.g., age). Hence, we propose a novel approach to introduce reputation independence for multiple sensitive attributes simultaneously. We then analyze the extent to which our approach impacts on discrimination and other important properties of the ranking system, such as its quality and robustness against attacks. Experiments on two real-world datasets show that our approach leads to less biased rankings with respect to multiple users’ sensitive attributes, without affecting the system’s quality and robustness

Security of Cyber-Physical Systems in the Presence of Transient Sensor Faults

This paper is concerned with the security of modern Cyber-Physical Systems in the presence of transient sensor faults. We consider a system with multiple sensors measuring the same physical variable, where each sensor provides an interval with all possible values of the true state. We note that some sensors might output faulty readings and others may be controlled by a malicious attacker. Different from previous works, in this paper we aim to distinguish between faults and attacks and develop an attack detection algorithm for the latter only. To do this, we note that there are two kinds of faults – transient and permanent; the former are benign and short-lived whereas the latter may have dangerous consequences on system performance.We argue that sensors have an underlying transient fault model that quantifies the amount of time in which transient faults can occur. In addition, we provide a framework for developing such a model if it is not provided by manufacturers. Attacks can manifest as either transient or permanent faults depending on the attacker’s goal. We provide different techniques for handling each kind. For the former, we analyze the worst-case performance of sensor fusion over time given each sensor’s transient fault model and develop a filtered fusion interval that is guaranteed to contain the true value and is bounded in size. To deal with attacks that do not comply with sensors’ transient fault models, we propose a sound attack detection algorithm based on pairwise inconsistencies between sensor measurements. Finally, we provide a real-data case study on an unmanned ground vehicle to evaluate the various aspects of this paper