الفهرس 
Chapter One OverviewOnly 14 pages are availabe for public view
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Abstract
Securing wireless sensor networks is considered to be one of the main challenges these days. Sensors must be well secured in case of gathering sensitive and critical data are transferred. Due to resource limitations in sensor networks, efficient security schemes must be implemented and developed continuously to avoid resource consumption. The main objective of this study is to introduce a new scheme for solving the problem of dynamic encryption keys for the WSNs motes to ensure message confidentiality while it’s traveling between sensor nodes and hosts inside and outside the network. The proposed solution will help to guarantee a secure connection between sensor nodes. It also helps in decreasing power consumption by reducing the resource requirements of the cryptographic mechanism. The scheme is tested using OMNET and applied to a WSN consists of 100 sensor nodes. The proposed scheme is applied to two different scenarios. The first one starts with high initial energy of each sensor equals 5 Joules. While the second is based on low initial sensor energy equals 0.5 Joule. Experimental results show that the proposed scheme has a great manner in saving energy up to a percent closes to 80% of the initial energy. All sensor nodes’ remaining energy and performance analysis over the network transmission were tested at 50, 150, 300, and 500 rounds. A low bit error rate has been successfully achieved and the scheme also achieves a minimum back-off duration besides a stable transmission state. Output randomness has been achieved during the interval [0.05 < P-Value<0.5].