Let’s break two-time pad!

Contents


Intro

Below is the problem sets about this attack. Stanford and Maryland

Here is the solutionStanford then Maryland

Main points

if the same key used twice, then the result of (c1 Xor c2) will reveal a lot information about the original messages.

For example, the space is very crucial. ‘ ‘ ^ ‘a’ = ‘A’ and ‘ ‘ ^ ‘A’ = ‘a’. When ‘ ‘ Xor with a letter then it will produce corresponding letter. So it is the very start to break two-time pad.


Attack

Once we know the drawbacks behind it, we could easily break it.

Everything is covered in my code above.

If you are a Chinese, you could read detail




blog comments powered by Disqus

Published

26 April 2015

Category

crypto

Tags