Hacker News new | ask | show | jobs
by teo_zero 76 days ago
I think the author is too quick to dismiss the impact of the plugboard.

> IC attacks only the rotor settings [...] Once you’ve found the right rotors and positions, you can solve the plugboard separately using frequency analysis.

So two steps: first solve for rotor settings with IC analysis, then solve the plugboard.

But IC analysis can't find the solution, just propose a lot of candidates among which a human can spot the correct one by looking for intelligible German text. And how can you spot intelligible German text if some letters are swapped by the plugboard?

1 comments

Yeah something is wrong there, and I don't see actual breaks in the post, though maybe I missed something. Solving the rotors to get to the plugboard isn't so easy! The permutation changes every character, as the rotors advance.