The Krypto K4 hints thread

First Gizmore, if you have a better place for this, feel free to move the thread.

So...As it turns out Kryptos K4 was never solved, which I personally find odd...
The K4 challenge is encrypted: OBKRUOXOGHULBSOLIFBBWFLRVQQPRNGKSSOTWTQSJQSSEKZZWATJKLUDIAWINFBNYPVTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR

The TLDR version: 1) Enigma, 2) check Enigma-Uhr 3) check Rejewski's methods used

Given the fact that it was built in 1990 and we are 2024...+30 years seems to me a very long time, while it really (I'm honest) didn't take long to see 1) the encryption algo used 2) the cycles and 3) that's for later.

First things first, the official hints:
- October 2010 the hint NYPVTT = BERLIN
- October 2014 the hint MZFPK = CLOCK

Turns out, it didn't ring a bell for many...But I'll tell you which clock it is, because it isn't a strange looking clock at all!

- January 2020 the hint QQPRNGKSS = NORTHEAST was given
- April 2020 the hint FLRV = EAST was given

And last time I checked it still wasn't solved...So on 20 August 2023 I wrote Jim Sandborn the following (the reason why I won't provide the solution):
'Whilst everyone is trying to break section 4 (assumption), I was thinking why you would have made it. So I believe that you made it, so we had a better understanding about the difficulty to crack something unknown. So I am going to tell some things and why it's then better not to crack it. Enigma means (in Dutch/Flemish: raadsel) so riddle. You want to let them solve the riddle and gain insight how hard this was for people like Alan Turing, Rewejski and many others. While you provided hints about the fourth section you did it very specific. Northeast for example was related to the line, so you gave away it's a transposition cipher. Also: the structure of the text, gives away that it is enigma encoded. Eg. Two Q's after each other, but still having a different decoded letter.'

Encryption algorithm used?
--> K4 is yet another polyalphabet substition cipher, named Enigma. Now I did make a mistake in that email about the rotors used. And it was because I only cracked another portion of it without cracking the rest.

So technically you can decode it, writing your own enigma system. But then you need to understand how enigma works. The other way to decode it, is by using the technique Rejewski used.

But here is WHY I am not providing solutions:
'You see humanity works this way: they seek a solution for something. They ask the creator for hints, if it's correct, etc. So they actually want shortcuts to solve it quicker. Now that's not how I work. If many people solved an encryption challenge, and I still didn't. Then that's 'frustrating', because you solved many others, they couldn't. But still it tells me, there is some lack of understanding for me. That's the frustration part.
Now suppose I would crack it (and share the result), then the world has the solution. But then this also implies, that the world is no longer going to search for the solution and this would just break the whole idea you have come up with. So that's why I decided: maybe it's best I don't start to decrypt it, even though I know how to do it. After all, I tried to understand your mindset, and to me, that has more value than the solution of the encryption challenge.

In other words, if we provide the solution, we take away the whole benefit of gaining insight on how hard things are. I hope you understand me.'

So why this thread? Because I gave additional hints, and by using this forum, one has it all in one place, instead of cluttered between twitter tweets. After all this place gathers many crypto enthousiasts...

Here are a couple of untold additional hints (which make it easier for you to decrypt Kryptos K4). Because I also noticed there was still a K5, and one needs K4 for it.

Additional hints:
1) The world didn't know until 22 august 2023 that is was Enigma. What gives it away are the QQ, SS positions of NORTHEAST. QQ = NO, SS = ST. Clear evidence that this cipher is ENIGMA.
2) On 23 august 2023 I gave an additional hint: SJQSSEKZZW is decrypted AREDECODED. Here is yet again the giveaway. SS -> ZZ -> SS = DE, ZZ - DE. This thing you witness is what we technically call cycles. Have a look at what Rejeweski did and what is meant by cycles. So in order to crack unswapped letters and/or swapped letters you need to turn your alphabet to the right. Eg.When the decryption alphabet is used the first time the S was on the D of the alphabet and the second turn on the E. Afterwards the same happened with the Z. So it turns. You should now be able to crack more and eventually have 15 out of 26 letters in a not so long time...
3) On that same day I also told the world, that he did something, K = K of BERLINCLOCK and the C cycles show that the cycles aren't following all the time. There is a reason for this all. How to break it: notepad, brains, logic.
4) On 10 April 2024 I gave additional hints:BERLINCLOCK refers not to what is on Wikipedia on this day, it refers to Enigma-Uhr, this was an addon for the Enigma I cipher machine. It was used by the Luftwaffe to improve the cipher security. It was manufactured by Konski and Kruger in Berlin. Makes more sense than that strange Wiki clock, doesn't it ;). So the Steckeruhr, plug-clock or Enigma-Uhr was introduced in July 1944. The difference: The Steckerbrett is self-reciprocal. This means that it if the configuration is exact, it can be both used to encrypt and decrypt.
5) The Enigma Uhr gives away implicitely that 16 non-swapped letters are used and 10 swapped letters. Now with the hint of AREDECODED, one should already have 15 out of 26 letters.
6) QQ, SS, ZZ tell you something, but the TT of BERLIN also tells you something...One needs to swap letters.

Now I personally believe that this can't last for another couple of years, if you know all of this. But nevertheless...I am planning my next hint at the end of August 2024. But maybe it's time I also crack it completely. By doing so, I have a deal with the world...Suppose each one of you follows my thumb rule: don't provide the solution. The solution will never be made public. So when I cracked it completely, I will print it out, together with a date and hide it behind something at my desk. My ancestors can thus still provide the solution.

But my personal belief...I believe with all those hints, many should now be able already to crack it anyway. At the end of August I probably provide the last hint, because otherwise it would be TOO easy to crack it. You already should have 15 out of 26 letters. 11 left...10 are probably swapped.

Happy cracking folks ;).

People always have a choice: if you pay Jim Sandborn and provide the solution, you will get your name on the history plate. If you don't, you give others the chance to crack it too, without knowing the solution.

The text is English of course.

I hope this was informative, and I'm rather confident, many of us can crack it by now.

For those of you trying to solve it. You might want to code a scritchmus or clock method. This will speed up your journey a bit, but it will also rule out human error mistakes. Which I sometimes made.

And it might be you will need to understand not only how the enigma Uhr or steckerbrett works, but Banburismus might come in handy as well.

It is best to start first without swapped letters, then you can see when you need a rotor notch and when there is an actually letter swap.

Hello XStreamke!
Maybe people can't solve this riddle because some of your hints are wrong.
You say that:
1. MZFPK = CLOCK, and
2. QQPRNGKSS = NORTHEAST

Which implies that there are two letters, K in the first hint and S in the second, that encrypt to themselves.
But we know that in a rotor-based encrypting machine like the Enigma was, this is not possible.
Cheers.