5
$\begingroup$

Just a short but really scary looking code breaking challenge.

It breaks down into a couple of sentences once cracked.

24141325121914011720242320110720150920201224161720111012190613080310160806252412191417050526212017171013

Improve this question
$\endgroup$

2 Answers 2

Reset to default
13
$\begingroup$

First step:

Split the digits into pairs:
Result is 24, 14, 13, 25, 12, 19, 14, 01, 17, 20, 24, 23, 20, 11, 07, 20, 15, 09, 20, 20, 12, 24, 16, 17, 20, 11, 10, 12, 19, 06, 13, 08, 03, 10, 16, 08, 06, 25, 24, 12, 19, 14, 17, 05, 05, 26, 21, 20, 17, 17, 10, 13.

Second step:

Convert 01 to a, 02 to b, 03 to c, ... 26 to z
Result is xnmylsnaqtxwtkgtoittlxpqtkjlsfmhcjphfyxlsnqeezutqqjm.

Third step:

Rotate 5 letters in the backward direction (or equivalently 21 in the forward direction).
This changes f to a, g to b, h to c, i to d, ..., y to t, z to u, a to v, b to w, c to x, d to y and e to z.
Result is sihtgnivlosrofbojdoogsklofegnahcxekcatsgnilzzupolleh.

Fourth step:

Reverse the string.
Result is hellopuzzlingstackexchangefolksgoodjobforsolvingthis.

Fifth (and final) step:

Add some spaces.
Result is hello puzzling stack exchange folks good job for solving this, which is the plain-text message.

A note about the message:

The original message had two typos in the plain-text message. Originally it was "24141325121914011720242320 16 0720150920201224161720111012190613080310160806252412191417050526 22 2017171013",
instead of
"24141325121914011720242320 11 0720150920201224161720111012190613080310160806252412191417050526 21 2017171013"
which used to produce the plain-text message hello quzzling stack exchange folks good job kor solving this, but the OP already fixed that.

Improve this answer
$\endgroup$
3
  • $\begingroup$ Step 6. Type correct "hello quzzling stack exchange folks good job kor solving this" -> "hello puzzling stack exchange folks good job for solving this" $\endgroup$
    – warspyking
    Commented Dec 14, 2014 at 13:05
  • $\begingroup$ Thanks for letting me know about the errors. I have fixed the errors in the post. $\endgroup$
    – Colorfully Monochrome
    Commented Dec 14, 2014 at 20:27
  • $\begingroup$ @ColorfullyMonochrome Ok, I have changed the answer to reflect that. $\endgroup$
    – Victor Stafusa
    Commented Dec 14, 2014 at 20:37
4
$\begingroup$

Splitting the digits into groups of two and taking letters

241413... = 24,14,13,... = XNM...

gives the length-52 string

'XNMYLSNAQTXWTPGTOITTLXPQTKJLSFMHCJPHFYXLSNQEEZVTQQJM'

This method is implicitly confirmed in that all the resulting indices are 1 through 26, which is unlikely in a random string of numbers.

I don't care to go further though because now it's just a random-looking string of letters, too short to do any meaningful cryptanalysis, and I see nothing better to do then throw methods at it until one works. I did try Caesar cipher though; none of the shifts produced anything meaningful.

Improve this answer
$\endgroup$
2
  • $\begingroup$ Actually, caesar shift was correct (ROT5) - then the result is backwards. $\endgroup$
    – Colorfully Monochrome
    Commented Dec 14, 2014 at 5:17
  • $\begingroup$ +1 for reasoning the 'split' is correct even without finding a clear text. $\endgroup$
    – BmyGuest
    Commented Dec 14, 2014 at 8:31

Your Answer

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

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