Kwame Osei Boateng

Comparative Analysis of Energy Usage of Hash Functions in Secured Wireless Sensor Networks

Security in wireless sensor network (WSN) has become an increasing necessity due to the diverse application areas being implemented. Application areas such as military surveillance and environmental monitoring need to be guided against node tampering and node subversion. Works carried out by wireless sensor network researchers pertaining to increasing the security of the network is significant. Node authentication is a suitable technique against node tampering and the introduction of false nodes. A way of authenticating nodes is by using Message Authentication Code (MAC); this is implemented using hash functions. The limited energy available to sensor nodes, have to be considered when selecting a hash function for implementation. In this paper, comparative analysis of some hash functions (MD-5, SHA-1, SHA-224, SHA-256, SHA-384 and SHA-512) were carried out. The functions were selected based on their popularity. The analysis was done to identify a short-list of hash functions that can be used when WSN hash related security techniques are being designed. The short-listed functions so identified were further analyzed in terms of their complexities. This was carried out by executing compiled codes and averaging the CPU time spent in executing a common scenario. The result of the analyses showed SHA-224 as the best hash function to be used when designing energy-conscious secured WSNs.

A Retrofit Design Science Methodology for Smart Metering Design in Developing Countries

Traditional meters present both the users and utilities providers with various challenges in developing countries. For instance utility providers must get access to their users premises to be able to read these meters or check fraudulent connections. Users on the other hand have to wait for months or more before knowing their utility consumptions or join long queues to purchase credit for the post-payment and pre-payment meters respectively. This paper seeks to propose a design that retrofits traditional meters on site into smart meters by adding embedded units for communication and control. The study was conducted using a modified Design Science Methodology referred to as Retrofit Design Science Research Methodology (RDSRM). RDSRM argues that, the artifact in context (Smart Meter) has undergone evaluation and acceptance as critical for solving a defined problem and that there are enough literature to support its relevance. The traditional meters were studied and the proposed system was designed using General Packet Radio Service (GPRS) technology for communication, and Peripheral Interface Controller (PIC). Network based applications were developed to present both the consumers and the utilities with the ability to interact with the meters remotely. An attempt was made to address identified security issues of smart metering by using Message Digest 5 (MD5) Algorithm in the design. The system was evaluated based on smart metering requirements. The GPRS Retrofitted Smart Metering System (GRSMS) will reduce the cost of deploying smart meters.

Tamper-aware authentication framework for wireless sensor networks

Sensor nodes once deployed onto the field are mostly provided with little or no attention making them prone to physical attacks by adversaries. Various security frameworks have been proposed to mitigate tampering; others also ensure authentication of sensor nodes. Energy is a limited resource and as such, the need to develop energy efficient frameworks that ensure authentication and thwart tampering of deployed sensor nodes. In this study, a framework comprising an authentication algorithm with a hardware-based tamper detection and recovery procedure is proposed. An interrupt-driven tamper detection and recovery mechanism is employed to aid the isolation of compromised nodes. MD-5, SHA-1, SHA-224, SHA-256, SHA-384 and SHA-512 hash functions were reviewed and simulation done to select the most energy-efficient option (SHA-224) for use with the authentication algorithm. The proposed framework was compared with other existing authentication frameworks in the area of energy efficiency. The result show that the proposed framework is the most energy-efficient. The proposed framework, TinySec, SenSec and MiniSec were analysed against node subversion and false node attacks; the proposed framework can detect compromised nodes in all two attacks but the rest were only potent against false nodes and not against node subversion.

Improving Vacant Channel Utilization in Shared TV White Space Spectrum

Television White Spaces (TVWS) are unused and unassigned channels called Vacant Channels (VCs) in the licensed broadband wireless spectrum allocated to TV broadcasters also called Primary Users (PUs). One of the major objectives for implementing TVWS technology in delivering broadband internet is to ensure the efficient utilization of VCs in wireless spectrum. To this end, the Geolocation Database (GLDB) has been widely accepted by regulators as the main technique for detecting VCs for use by unlicensed Secondary Users (SUs), because it offers better prospects in preventing harmful interference to licensed PUs. However, in the open literature, little attention has been given to its capacity to ensure that VCs assigned to SUs for data transmissions are fully utilized. There is the tendency for SUs to misuse VCs assigned to them, by staying idle for long periods without transmitting since there are no proper monitoring mechanisms. This denies other SUs the opportunity to access same channels, creating congestion and long queues. To mitigate this underutilization and ‘denial-of-use’ problem, we propose a Middleware architectural solution, called Database Bandwidth Regulator (DBR) for the GLDB to ensure efficient utilization of VCs. The DBR middleware makes use of the Bandwidth Consumption Cost (BCC) of SUs for data transmissions. We use Discrete Event Simulation (DES) technique to model and simulate both the regulated/normal GLDB and our DBR middleware GLDB. Statistical analysis of simulated results shows that VC utilization is improved by a factor of 4.1% with our DBR middleware intervention as compared to the regulated/normal GLDB.

The adoption of socio- and bio-inspired algorithms for trust models in wireless sensor networks: A survey

Summary nThe security of a wireless sensor network is greatly increased with increasing levels of trustworthiness of nodes on the network. There are a number of trust models proposed that use various trust evaluation methods. The paper categorises trust evaluation methods for wireless sensor networks into socio-inspired, bio-inspired, and analytical methods. Biologically inspired methods and socio constructs are rarely used in the design of trust schemes as opposed to analytical methods (probability, agent based, fuzzy, etc). The paper discusses existing bio- and socio-inspired–based trust schemes implemented for wireless sensor networks, viz quality-based distance vector protocol, enhanced bio-inspired trust and reputation model for wireless sensor network, bio-inspired trust routing protocol, machine learning–based bio-inspired trust and reputation model, socio-psychological trust and reputation model, and finally reputation framework for sensor network. The contributions, trust evaluation methods and limitations of recent trust models (i.e. analytical based, biological and socio-inspired models) are discussed in this paper. The pros and cons of analytical, socio, and biologically inspired algorithms for computing are outlined to easily ascertain the relevance of adopting either biological or socio-inspired approaches for solving trust-related problems in wireless sensor networks.