I am trying to understand the non-optimized known plaintext attack on A5/2 from Barkan, Bikan and Keller.

I don't understand the construction of the equation system: $$S_{R4_1} * S_1 = k$$

Where $S$ is the system's matrix and $k=k_1||k_2||k_3||k_4$.

How do I create the system's matrix $S_{R4_1}$ and $S_1$?

  • $\begingroup$ Formatting hint: you can use \$\$ prefix / appendix instead of a single \$ to create a centralized block formula. $\endgroup$ – Maarten Bodewes Dec 1 '17 at 22:05

Your Answer

By clicking "Post Your Answer", you acknowledge that you have read our updated terms of service, privacy policy and cookie policy, and that your continued use of the website is subject to these policies.

Browse other questions tagged or ask your own question.