As part of a CS397 project, I did a lot of research into the RC4 Stream Cipher just to try my hand at crypto research. I was supposed to be researching general wireless vulnerabilities, but I was obsessed. I investigated all sorts of attacks, weaknesses, formalisms, etc for the RC4 cipher itself. In the end, I decided the easiest new contribution would be to improve the bounds on the Knudson Attack on RC4 by implementing the state array as a probability distribution in order to find the exact distribution over the state table after the Key Scheduler ran, and then to use this to help Knudson's algorithm generate more accurate guesses. All said and done I discovered exactly what Aurther Roo surmised back in 1995, just months after the RC4 source leaked. This was when I decided that crypto research wasn't for me.
↧