3
$\begingroup$

Below is what I have. I know that X is padding, and I've tried ROT1-25. I assume it's substitution, but I don't see it.

TUAUC IHCRN OSELL CDXNE AHEX

$\endgroup$
17
$\begingroup$

The message is very short, but a cursory frequency analysis tells you that ...

... the letter distribution isn't far from the distribution in English texts: E is the most frequent letter, along with C. There are some Ls, some Hs to go with the Cs, and so on. This is more likely a transposition cipher than a substitution cipher.

The first letter is T and ...

... if you look at the second letter of the second block and the third letter of the third block, they are H and E, which conventiently spells THE. Rearrange the letters in a rectangle of width 6:

T U A U C I
H C R N O S
E L L C D X
N E A H E X
You can now read the message column-wise from top to bottom.

The message reads:

The nuclear launch code is XX.

Use it wisely. :)

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.