0
$\begingroup$

enter image description here

I was going through this question and intuition came that same message can be used to break security but I an not able formalize it well...can someone help how to create chosen ciphertext attack formally so that adversary wins with significant probability.

Improve this question
$\endgroup$
4
  • $\begingroup$ Hint: consider the malleability of countermode; that is, given the encryption of $E_k(P_1)$, you can convert it into the encryption $E_k(P_2)$ (assuming that you know both $P_1$ and $P_2$, and they're the same length...) $\endgroup$
    – poncho
    Mar 22, 2021 at 21:09
  • $\begingroup$ can you please more elaborate.. $\endgroup$
    – Sam
    Mar 22, 2021 at 21:21
  • $\begingroup$ If this is homework, you're supposed to figure it out... $\endgroup$
    – poncho
    Mar 22, 2021 at 21:51
  • $\begingroup$ it is not a homework i am solving chapter 9 of boneh shoup book and it is 9.4 of that book .....just that i am stuck at this ..i thought for 1 day.....but i am not getting idea of it $\endgroup$
    – Sam
    Mar 22, 2021 at 22:06

0

Reset to default

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct.