Secrecy algorithms for wireless networks

The broadcast nature of wireless communications makes it more vulnerable to eavesdropping. As the application of wireless communication has been ubiquitous in our daily life, it is important to secure the wireless communication as a lot of data we transmitting by wireless is private or confidential. Now the world is always using cryptography method to secure the data. But as it has the nature of using computational complexity, it can’t guarantee that the secrecy will be absolutely achieved, and what’s more, as computer’s computational power is increasing and prices are declining, the cost needed to break a cipher will become cheaper and cheaper. Wired Equivalent Privacy (WEP) is an example that used to be employed as an encryption method but now can be broken by some free software within 1 minute. In information theory, there are mathematical ways to increase the equivocation rate of eavesdropper of data it received, for the purpose to achieve wireless secrecy. Here we are trying to use a more practically method to explain the wireless secrecy, which is differences of bit error rates between honest receiver and eavesdropper. If bit error rates of the eavesdropper is much higher than the honest receiver, the data eavesdropper received is could be useless as there are too many errors while data the honest receiver received is useful. In such a case, wireless secrecy is achieved. In this project, the performance of Convolutional Catastrophic Code and Low Density Parity Check Code is tested with different modulation methods. Discussion on how the coding schemes could be used to achieve wireless secrecy by exploiting the physical channel advantage of the honest receiver than eavesdropper is made. At the end, we conclude that the Convolutional Catastrophic Code and Low Density Parity Check Code are good to help achieve the wireless secrecy. And in the future we can use some method to tune the performance to achieve our requirement on secrecy.Bachelor of Engineering (Computer Engineering