But after the 2020 clues (another 13 letters), it became clear that it wasn't any single ACA cipher type, and it was probably something very difficult (because of K4's very low index of coincidence, i.e. 0.036 just below "random" 26-letter text at 1/26, plus the huge number of revealed plaintext letters "in place" i.e. letter-for-lettter correspondence).
That plausibly left a combination of two or more well-known cipher types, but if they were somewhat complex ciphers, the chance of solution would be rather remote.
Hence I always thought a "good" end to the puzzle would be like the book "Masquerade" by Kit Williams where the only guy in cahoots with the creator (Bamber Gascoigne) thought the initial puzzle was an unrealistic challenge, but Williams released clues which enabled two schoolteachers to solve it. So that part was satisfactory, even if hardly anybody remembers the solvers' names!
In contrast, the cribs for K4 haven't helped at all.
Good puzzles, even hard ones, should have some idea which way to approach them and should offer a method of attack other than brute force.
You would think that one of the lessons of that is that someone could jump in right at the end and solve it after several clues were released. That hasn't worked with K4, which is increasing people's skepticism.
Edit: Unless the one time pad is a well known relative document, such as the Declaration of Independence.
The article left me with a nagging question: Doesn’t the designer of the codes deserve a share of the proceeds of the auction? He’s still alive according to Wikipedia. It sounds like the unsolved code is what makes the art especially valuable. Was the cryptographer’s effort a “work for hire”, so he doesn’t get anything from the sale?
As Kryptos gots a huge amount of media attention in 1999, references to him changed from "chairman of A cryptographic center" to "chairman of [THE] CIA's cryptographic center" when it doesn't even seem that it has such a center.
And the featured story (around 52:00 of the video) has him apparently claiming credit for helping solve a Caesar cipher!
https://web.archive.org/web/19990501000000*/http://www.tecse...
He is an artist, not a mathematician. It’s a physical reveal for this layer of the copper onion.
Perhaps a 3D artist can model it and run some simulations with light.
AT FIRST LIGHT FACE EAST. ALIGN WITH THE RIM SHADOW. READ EDGE TO EDGE TO FIND THE FINAL CODE.
You most certainly need to be there and k4 is instructions. I’m not sending the guy $50 to check my answer though
So head north of it and use the shadows rim and 4/4/11/4 reveals and the Berlin clock sequence. Maybe on NOVEMBER NINE AT DAWN if you simulate it.
