Minimum Energy Broadcast in Duty Cycled Wireless Sensor Networks

We study the problem of finding a minimum energy broadcast tree in duty cycled wireless sensor networks. In such networks, every node has a wakeup schedule and is awake and ready to receive packets or transmit in certain time slots during the schedule and asleep during the rest of the schedule. We assume that a forwarding node needs to stay awake to forward a packet to the next hop neighbor until the neighbor is awake. The minimum energy broadcast tree minimizes the number of additional time units that nodes have to stay awake in order to accomplish broadcast. We show that finding the minimum energy broadcast tree is NP-hard. We give two algorithms for finding energy-efficient broadcast trees in such networks. We performed extensive simulations to study the performance of these algorithms and compare them with previously proposed algorithms. Our results show that our algorithms exhibit the best performance in terms of average number of additional time units a node needs to be awake, as well as in terms of the smallest number of highly loaded nodes, while being competitive with previous algorithms in terms of the total number of transmissions and delay

An End-to-End Authentication Mechanism for Wireless Body Area Networks

Wireless Body Area Network (WBAN) ensures high-quality healthcare services by endowing distant and continual monitoring of patients' health conditions. The security and privacy of the sensitive health-related data transmitted through the WBAN should be preserved to maximize its benefits. In this regard, user authentication is one of the primary mechanisms to protect health data that verifies the identities of entities involved in the communication process. Since WBAN carries crucial health data, every entity engaged in the data transfer process must be authenticated. In literature, an end-to-end user authentication mechanism covering each communicating party is absent. Besides, most of the existing user authentication mechanisms are designed assuming that the patient's mobile phone is trusted. In reality, a patient's mobile phone can be stolen or comprised by malware and thus behaves maliciously. Our work addresses these drawbacks and proposes an end-to-end user authentication and session key agreement scheme between sensor nodes and medical experts in a scenario where the patient's mobile phone is semi-trusted. We present a formal security analysis using BAN logic. Besides, we also provide an informal security analysis of the proposed scheme. Both studies indicate that our method is robust against well-known security attacks. In addition, our scheme achieves comparable computation and communication costs concerning the related existing works. The simulation shows that our method preserves satisfactory network performance

Sub-vocal speech pattern recognition of Hindi alphabet with surface electromyography signal

Recently electromyography (EMG) based speech signals have been used as pattern recognition of phoneme, vocal frequency estimation, browser interface, and classification of speech related problem identification. Attempts have been made to use EMG signal for sub-vocal speech pattern recognition of Hindi phonemes fx1,fx2,fx3,fx4 and Hindi words. That provides the command sub-vocally to control the devices. Sub-vocal EMG data were collected from more than 10 healthy subjects aged between 25 and 30 years. EMG-based sub-vocal database are acquired from four channel BIOPAC MP-30 acquisition system. Four pairs of Ag-AgCl electrodes placed in the participant neck area of skin. AR coefficients and Cepstral coefficients were computed as features of EMG-based sub-vocal signal. Furthermore, these features are classified by HMM classifier. H2M MATLAB toolbox was used to develop HMM classifier for classification of phonemes. Results were averaged on 10 subjects. An average classification accuracy of Ka is found to be 85% whereas the classification accuracy of Kha and Gha is in between 88% and 90%. The classification accuracy rate of Ga was found to be 78% which was lesser as compared to Kha and Gha

A Trust Model for Edge-Driven Vehicular Ad Hoc Networks Using Fuzzy Logic

Trust establishment among vehicles is essential for vehicular ad hoc networks (VANETs) as it directly impacts the security and privacy of vehicular communication. Many trust estimation approaches have been introduced, however, they often suffer from ensuring effective trust for vehicles. In fact, existing approaches do not involve all malevolent properties of vehicles in trust computation and can not properly handle the content tampering attack, which eventually affect the accuracy of the estimated trust. Moreover, most of them do not consider the uncertainty of VANET arising from vehicles’ mobility, their inaccurate/incomplete data dissemination, and the wireless communication channels, which also affects the reliability of the trust estimation. To address these limitations, this paper proposes a fuzzy logic-based approach to estimate vehicles’ trust. The new approach considers three trust factors, captured by fuzzy sets, to model malicious properties of a vehicle. Further, it involves a new data-centric parameter to capture the impact of content tampering on trust evaluation. In addition, the new approach includes an inter-edge trust transfer mechanism to carry forward a vehicle’s trust when it switches to a new edge server to ensure a seamless operation in VANETs. We evaluate the performance of the proposed scheme against the state-of-the-art approaches using both synthetic and real-world datasets. The experimental results reveal that it outperforms existing schemes in detecting malicious vehicles with higher recall, precision, and accuracy. Further, the new scheme reduces end-to-end delay and messages per data packet compared to other schemes

A multi‐device user authentication mechanism for Internet of Things

Abstract The advent of the Internet of Things (IoT) enables different customized services to ease the day‐to‐day life activities of users by utilizing information attained through the internet connectivity of low‐powered sensing devices. Due to device diversity and resource constraints of participating devices, IoT is vulnerable to security attacks. Consequently, authentication is the fundamental measure for using IoT services in the context of network security. IoT devices’ resource captivity makes designing robust and secure authentication mechanisms challenging. Besides, existing user authentication mechanisms are designed assuming a user always accesses an IoT environment using a particular device. However, nowadays, most users employ multiple devices to access the internet; subsequently, it needs an authentication mechanism to handle this diversity. This paper addresses this limitation and proposes a new One‐Time Password (OTP)‐based user authentication scheme supporting user access from multiple devices in an IoT environment. We verify the proposed scheme using widely used BAN logic, AVISPA tool, and informal security analysis, guaranteeing that our scheme preserves the necessary security features. Comparative performance analysis shows that our scheme achieves comparable computation, storage, and communication costs concerning existing works. Moreover, simulation results demonstrate that the proposed method also sustains satisfactory network performance

Secure Access to Outsourced Data from Resource-Constrained Devices

Resource-constrained mobile devices, such as smart phones, wearables, and IoT devices, have produced manyexciting and innovative applications by leveraging the extensive data storage and processing abilities of the cloud.Cloud data is expected to be stored in encrypted form to minimise the consequences of data breaches that arebecoming more and more common. Nonetheless, processing encrypted data in resource-constrained devices isexpensive in many aspects due to their limitations in processing capacity, bandwidth, storage, and battery power.Therefore, designing secure cloud data access mechanisms that are light-weight and can provide fine-grained readand write access for these devices is a very challenging problem.In this thesis we present the design of a novel architecture for performing secure read and write operations onoutsourced data encrypted with Ciphertext-Policy Attribute-based Encryption (CP-ABE) from clients using resourceconstraineddevices. We make three contributions. First, we address one of the fundamental shortcomings of CPABEschemes of not being able to maintain the data owner control during the write operation. We design andimplement a light-weight cloud data access mechanism that ensures data owner control and supports small-scaledata collaboration where users access cloud data through smart phones. Second, we propose a robust read/writeaccess mechanism for cloud data for large-scale scenarios where multiple attribute authorities authenticate users'attributes and generate decryption keys, and users from various domains access the outsourced data. Finally, wepropose an outsourced data access mechanism for power-constrained devices, such as wearables and IoT devices,in a multi-authority and multiple domain setting that overcomes the shortcoming of CP-ABE not being able to ensurethe confidentiality of access policies from all unauthorised entities.For all three contributions, we conduct detailed analysis to ensure that the required security properties are satisfied.We implement all protocols and thoroughly analyse their performance. Our results indicate that the proposedprotocols can be implemented without imposing significant processing, communications, and energy overheads onthe resource-constrained devices