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Abstract
The ever increasing demand for performance and data security improvement in Wireless Local Area Network (WLAN) has motivated increasing the difficulties to crack the system by man-in-the middle attacks. There are two primary and main objectives of this thesis to enhance data security in WLAN. The first objective is the enhancement of identities-exchange and key-exchange during authentication process. The second objective is the investigation of a proposed symmetrical encryption algorithm based on key-updating to enhance the performance of data-security in WLAN.
The current asymmetrical encryption algorithms are used to authenticate the devices in WLAN to each other. They are used to exchange the identities and the keys in a secret channel during the authentication process. This thesis investigates the problems of identities-exchange. The enhancement of the identities-exchange and key-exchange stages during the authentication process has been suggested and studied in the thesis to solve the drawbacks of the traditional asymmetrical encryption algorithms.
Next, the investigation of a proposed symmetrical encryption to encrypt the data during the data-exchange process gives a new approach to increase the difficulties to the man-in-the middle attacks to crack the system. The key-updating with each packet is the new approach to solve the problem of the fixed-key used to encrypt/decrypt the data with all packets in WLAN. A Comparative study between the proposed symmetrical encryption algorithms and the other algorithms is presented in the thesis. Proposed symmetrical encryption algorithm is applied on a text, voice, and image messages as practical applications of the proposed symmetrical encryption algorithm.
Finally, the man-in-the middle attacks can broadcast noise signals in WLAN channels to prevent the data to reach correctly to the end-user. The quality of the received image is measured for the proposed and the traditional symmetrical encryption algorithms to represent the ability to resist the noise. A comparative study of these algorithms with respect to noise-resistance is done by using the image message.