So here’s what I’m working on with Kryptos right now.  I’ve thought before about transposition acting as the masking technique on K4 and am revisiting it.  I recently tried Bifid on K4 as is and was able to build a key that placed “BERLIN” in the right spot.  Trouble was, the key wasn’t remotely close to what you’d expect given the conventions of a keyed-Bifid.

I started to wonder that I hadn’t taken the “masking technique” into consideration or if the ciphertext was just in the wrong order.  I’m not saying I was right with Bifid, it’s more that I’m returning to the supposed 1st layer of K4, some kind of masking technique that removes our ability to analyze the ciphertext in order to help decryption.  I originally thought we would need to remove the letters to have a 90 letter grid but I’m not sure I was on the right track before.

Transposition would be easy, would break up digraphs and with some of the polygraphic ciphers make them impossible to solve.

Sanborn is an artist and thinks visually.  I’m tentatively thinking right now that Scheidt helped him design a clue built into the ciphertext of K4 that would help one reverse the transposition.  I’m thinking that the word KRYPTOS that you can see split onto the edges is not an accident and if we can simply reverse the transposition to line up those 7 letters and then take that adjusted ciphertext that we will be able to make some progress.  It’s not impossible to write the plaintext to give KRYPTOS in the output.  It’s also not impossible for Sanborn to customize the transposition however he sees fit.  As long as he followed some rule or set of rules for scrambling it then all we have to do is realign the letters.

That’s my idea.