Muttukrishnan Rajarajan

City, University of London · Centre for Cyber Security Sciences (CCySS)

Cloud computing adoption has been increasing rapidly amid COVID-19 as organisations accelerate the implementation of their digital strategies. Most models adopt traditional dynamic risk assessment, which does not adequately quantify or monetise risks to enable business-appropriate decision-making. In view of this challenge, a new model is proposed...

The growth of IoT devices is so rapid that several billions of such devices would be in use in a span of four-year period. Essential security mechanisms need to be put in place to curb several security attacks prevalent in IoT. Access control is an important security mechanism that ensures legitimate and controlled access to critical and limited re...

Autonomous vehicles are taking a leap forward by performing operations without human intervention through continuous monitoring of their surroundings using multiple sensors. Images gathered through vehicle mounted cameras can be large, requiring specialized storage such as cloud. However, cloud data centres can be prone to security and privacy chal...

Ransomware attacks pose a serious threat to Internet resources due to their far-reaching effects. It’s Zero-day variants are even more hazardous, as less is known about them. In this regard, when used for ransomware attack detection, conventional machine learning approaches may become data-dependent, insensitive to error cost, and thus may not tack...

With the widespread use of Internet of Things (IoT) in various applications and several security vulnerabilities reported in them, the security requirements have become an integral part of an IoT system. Authentication and access control are the two principal security requirements for ensuring authorized and restricted accesses to limited and essen...

Cloud computing adoption has been increasing rapidly amid COVID-19 as organisations accelerate the implementation of their digital strategies. Most models adopt traditional dynamic risk assessment, which does not adequately quantify or monetise risks to enable business-appropriate decision-making. To address this issue, we propose a Cloud Enterpris...

The diverse range of Internet of Things (IoT) devices in smart homes results in users having to deal with a variety of technologies with different and incompatible user authentication methods. Continuous authentication offers an intelligent solution to this problem, although its application within IoT is currently in its infancy, and the limitation...

Cloud computing adoption has been increasing rapidly amid COVID-19 as organisations accelerate the implementation of their digital strategies. Most models adopt traditional dynamic risk assessment, which does not adequately quantify or monetise risks to enable business-appropriate decision-making. To address this issue, we propose a Cloud Enterpris...

The security of IoT devices is a major concern that needs to be addressed for their wide adoption. Users are constantly seeking devices that are faster and capable of holding large amounts of data securely. It is purported that water has memory of its own and the ability to retain memory of the substances that are dissolved into it, even after bein...

Ransomware attacks are hazardous cyber-attacks that use cryptographic methods to hold victims’ data until the ransom is paid. Zero-day ransomware attacks try to exploit new vulnerabilities and are considered a severe threat to existing security solutions and internet resources. In the case of zero-day attacks, training data is not available before...

Cryptography has been used from time immemorial for preserving the confidentiality of data/information in storage or transit. Thus, cryptography research has also been evolving from the classical Caesar cipher to the modern cryptosystems, based on modular arithmetic to the contemporary cryptosystems based on quantum computing. The emergence of quan...

As the world calls it, data is the new oil. With vast installments of Industrial Internet-of-Things (IIoT) infrastructure, data is produced at a rate like never before. Similarly, artificial intelligence (AI) and machine learning (ML) solutions are getting integrated to numerous services, making them "smarter". However , the data remains fragmented...

The traditional power network has now evolved into the smart grid, where cyber technology enables automated control, greater efficiency, and improved stability. However, this integration of information technology exposes critical infrastructure to potential cyber-attacks. Furthermore, the interdependent nature of the grid’s composite information an...

The removal of tartrazine dye from aqueous solution using g-C3N4/Fe3O4 nanocomposites was studied. The g-C3N4/Fe3O4 nanocomposites were synthesized using simple co-precipitation method. The synthesized nanocomposites were characterized by spectral (UV-Vis DRS, FT-IR) and analytical (PXRD, SEM, EDAX, HRTEM) techniques. Photodegradation of tartrazine...

The outbreak of the COVID-19 virus has caused widespread panic and global initiatives are geared towards treatment and limiting its spread. With technological advancements, several mechanisms and mobile applications have been developed that attempt to trace the physical contact made by a person with someone who has been tested COVID-19 positive. Wh...

In the present work biogenic synthesis of silver nanoparticles using Cissus quadarangularis aqueous leaf extract and their evaluation of antimicrobial activities. The synthesized nanoparticles were confirmed by, X-ray diffraction (XRD), UV–visible absorption (UV–Vis), Scanning electron microscopy (SEM) and Fourier transform infra-red (FT-IR) spectr...

Traditional power grids are evolving to keep pace with the demands of the modern age. Smart grids contain integrated IT systems for better management and efficiency, but in doing so, also inherit a plethora of cyber-security threats and vulnerabilities. Denial-of-Service (DoS) is one such threat. At the same time, the smart grid has particular char...

The automotive industry is witnessing an accelerated growth in digital innovations that turn modern vehicles into digital systems. This makes the security of modern vehicles a crucial concern as they have evolved into cyber-physical and safety-critical systems. Therefore, stateful identity management and continuous access control have become a para...

In the present work, we have demonstrated the fabrication of catechol (CC) biosensor based on reduced graphene oxide (rGO) decorated β-cyclodextrin (β-CD) nanosheet immobilized using nafion (Nf) on modified GCE (glassy carbon electrode). The rGO/β-CD nanocomposite is synthesized through sonochemical approach and characterized by spectral (UV–visibl...

Cryptography has been used from time immemorial for preserving the confidentiality of data/information in storage or in transit. Thus, cryptography research has also been evolving from the classical Caesar cipher to the modern cryptosystems based on modular arithmetic to the contemporary cryptosystems based on quantum computing. The emergence of qu...

Mn, Zr co-doped Ag2O nanoparticles (NPs) were blended through a wet chemical strategy, and the physicochemical properties of doped and co-doped silver oxide nanoparticles were characterized using X-ray diffraction, UV-DRS visible spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy with energy dispersive X-ray spectro...

Security of data has always been a contested issue since the internet became the way of life. The internet and Web 2.0 followed by Web 3.0 have enabled many applications for the use of the citizens. E-government is one of them. Questions have always been raised about the security of data in E-government applications and services. Saudi Arabia is on...

Traditional power grids are evolving to keep pace with the demands of the modern age. Smart grids contain integrated IT systems for better management and efficiency, but in doing so, also inherit a plethora of cyber-security threats and vulnerabilities. Denial-of-Service (DoS) is one such threat. At the same time, the smart grid has particular char...

The SrWO4/Bi2O3 nanocomposite was gotten by co-precipitation process and described by X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (UV–vis DRS), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HR-TEM), energy dispersive X-ray analysis (EDX), T...

In this study, we demonstrate a facile approach for the synthesis of strontium tungstate (G-SrWO4) using Pomelo leaf extract via the sonochemical method. The electrocatalytic performance of G-SrWO4 solubilized Nafion (Nf) (G-SrWO4/Nf) modified GC electrode was evaluated for uric acid (UA) detection. The characteristic properties of the prepared G-S...

In a rapidly changing IT environment, access to the resources involved in various projects might change randomly based on the role-based access control (RBAC) system. Hence, the security administrator needs to dynamically maintain the role assignments to users for optimizing user-role assignments. The manual updation of user-role assignments is pro...

This book presents the recent research adoption of a variety of enabling wireless communication technologies like RFID tags, BLE, ZigBee, etc., and embedded sensor and actuator nodes, and various protocols like CoAP, MQTT, DNS, etc., that has made Internet of things (IoT) to step out of its infancy to become smart things. Now, smart sensors can col...

LoRaWAN, part of the long range Internet of Things (IoT) technologies, is a Low Power Wide Area (LPWA) protocol that enables communication between the battery operated resource constrained devices. Although LoRaWAN provides system-level security, these networks are based on a basic assumption of trust between the network server and the user, which...

The proliferation of IoT in various technological realms has resulted in the massive spurt of unsecured data. The use of complex security mechanisms for securing these data is highly restricted owing to the low-power and low-resource nature of most of the IoT devices, especially at the Edge. In this work, we propose to use blockchains for extending...

Privacy-preserving applications allow users to perform on-line daily actions without leaking sensitive information. The privacy-preserving scalar product is one of the critical algorithms in many private applications. The state-of-the-art privacy-preserving scalar product schemes use either computationally intensive homomorphic (public-key) encrypt...

This chapter addresses the application of machine learning algorithms to detect attacks against smart grids. Smart grids are the result of a long process of transformation that power systems have been through, relying on Information and Communication Technology (ICT) to improve their monitoring and control. Although an objective of this convergence...

Among numerous metal oxide based nanocomposites, the polymer incorporated nanocomposites has received fascinated attention as promising electrode materials for inexpensive nonenzymatic glucose sensor. In this study, development of a sensitive and selective glucose sensor was fabricated using molybdenum trioxide (MoO3) via sol-gel method. The synthe...

Privacy-preserving applications allow users to perform on-line daily actions without leaking sensitive information. Privacy-preserving scalar product is one of the critical algorithms in many private applications. The state-of-the-art privacy-preserving scalar product schemes use either computationally intensive homomorphic (public-key) encryption...

In today’s globalized world, businesses and governments rely heavily on technology for storing and protecting essential information and data. Despite the benefits that computing systems offer, there remains an assortment of issues and challenges in maintaining the integrity and confidentiality of these databases. As professionals become more depend...

The hexavalent Chromium (Chromium (VI) (or) Cr⁶⁺) is considered as the most toxic element that directly affects the environment and the human cycle adversely. Therefore, in the present study we proposed a sensitive and selective electrochemical sensor for the detection of Cr⁶⁺ in various water samples using graphene carbon nitride decorated with si...

Herein, we report a simple synthesis, characterization and photocatalytic degradation application of composite NiO-WO₃ nanoparticles. The nanoparticles were synthesized by facile low-temperature method and characterized by several techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM)...

This paper describes a highly sensitive and selective electrochemical sensing of folic acid (FA) using vanadium pentoxide decorated graphene carbon nitride covalently grafted polyvinyl alcohol modified GC electrode (V2O5/G-C3N4/PVA/GCE). The V2O5/G-C3N4/PVA nanocomposite was synthesized by an in-situ oxidative polymerization method and characterize...

Blockchain systems are being rapidly integrated in various technologies, with limited work on the effect of the underlying network topology on the blockchain performance. In this work, we investigate the significance of each network node on the overall blockchain performance. This is assessed by selecting critical nodes according to different criti...

Global system for mobile communication (GSM) is widely used digital mobile service around the world. Although GSM was designed as a secure wireless system, it is now vulnerable to different targeted attacks. There is a need to address security domains especially the confidentiality of communication. This paper presents a novel framework for end to...

In the recent past, few works have been done by combining attribute-based access control with multi-user PEKS, i.e., public key encryption with keyword search. Such attribute enabled searchable encryption is most suitable for applications where the changing of privileges is done once in a while. However, to date, no efficient and secure scheme is a...

This paper describes a selective and sensitive detection of bronchodilators (theophylline) using an aloe vera plant extract decorated iron tungstate nanorods (AFW) immobilized Nafion (Nf) modified glassy carbon electrode (GCE) (AFW/Nf/GCE). The AFW was synthesized by the co-precipitation method and characterized by UV–visible spectroscopy, x-ray di...

Internet of Things (IoT) widely use analysis of data with artificial intelligence (AI) techniques in order to learn from user actions, support decisions, track relevant aspects of the user, and notify certain events when appropriate. However, most AI techniques are based on mathematical models that are difficult to understand by the general public,...

In the present work, a novel cupric oxide decorated on β-cyclodextrin (CuO/β-CD) nanocomposite was synthesized by sonochemical method. The CuO/β-CD nanocomposites were characterized by UV–vis, Raman, FT-IR, FE-SEM, mapping analysis, XRD techniques. Fascinatingly, the CuO/β-CD nanocomposite Nafion (Nf) solubilized modified glassy carbon electrode (C...

A novel and selective electrochemical sensing of nicotine is studied using copper tungstate decorated reduced graphene oxide nanocomposite (CuWO 4 /rGO) nafion (Nf) immobilized GC electrode (GCE). The CuWO 4 /rGO nanocomposite is synthesized using sonication method and characterized by HR-TEM (High resolution transmission electron microscopy), SEM...

Determination of glucose plays very important part in diagnostics and management of diabetes. Nowadays, determination of glucose is necessary in human health. In order to develop the glucose biosensor, polymer modified catalytic composites were fabricated and used to detect glucose molecules. In this work, NiO nanostructure metal oxide (NMO) was fa...

A novel electrochemical sensor based on iron tungstate doped tin oxide nanocomposite Nafion (FeWO4/SnO2/Nf) immobilized modified glassy carbon electrode (GCE) is fabricated to determine hydroquinone (HQ) in this present study. The structural morphology and phase of FeWO4/SnO2 nanocomposite are characterized by X-ray powder diffraction (XRD), energy...

Botnets have been part of some of the most aggressive cyberattacks reported in recent years. To make them even harder to be detected and mitigated, attackers have built C&C (Command and Control) infrastructures on top of popular Internet services such as Skype and Bitcoin. In this work, we propose an approach to detect botnets with C&C infrastructu...

Glucose detection is extremely necessary in several zones like foodstuff industries, analytical field, clinical diagnostics and biotechnology. In particular, diabetes mellitus which is a common chronic disease that threatens to the human health. To avoid this trouble, glucose recognition is significant. In this work, a novel vanadium dioxide (VO2)...

An eco-friendly ZnFe2O4/CeO2 nanocomposites as visible light photocatalysts with different mole ratios were successfully fabricated by sonochemical method. The nanocomposites material was characterized various analytical techniques such as X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (DRS), fourier transform infrared spectroscop...

The propagation approach of a botnet largely dictates its formation, establishing a foundation of bots for future exploitation. The chosen propagation method determines the attack surface and, consequently, the degree of network penetration, as well as the overall size and the eventual attack potency. It is therefore essential to understand propaga...

In this study, we produce a new continuous authentication scheme for gesture-typing on mobile devices. Our scheme is the first scheme that authenticates gesture-typing interactions in a word-independent format. The scheme relies on groupings of features extracted from the word gesture after it has been reduced to parts common to all gestures. We sh...

Botnets have been part of some of the most aggressive cyberattacks reported in recent years. To make them even harder to be detected and mitigated, attackers have built C&C (Command and Control) infrastructures on top of popular Internet services such as Skype and Bitcoin. In this work, we propose an approach to detect botnets with C&C infrastructu...

Internet of Things (IoT) systems can often pose risk to users' privacy via disclosure of personal information to third parties. In this paper, we argue that to assess privacy risks associated with IoT systems, an automated solution is required due to the increasing pervasiveness and complexity of deployed IoT systems. We propose requirements for an...