The Rail Fence Cipher (also called a zigzag cipher) is a form of transposition cipher that derives its name from the way in which it is encoded. In the rail fence cipher, the plain-text is written downwards and diagonally on successive “rails” of an imaginary fence, then moving up when we reach the bottom rail. When we reach the top rail, the message is written downwards again until the whole plain-text is written out. The message is then read off in rows. For example, if we have 3 “rails” and a message of ‘WE ARE DISCOVERED. FLEE AT ONCE’, the cipherer writes out:
W . . . E . . . C . . . R . . . L . . . T . . . E . E . R . D . S . O . E . E . F . E . A . O . C . . . A . . . I . . . V . . . D . . . E . . . N . .
Then reads off to get the ciphertext:
WECRL TEERD SOEEF EAOCA IVDEN
If it needed padding to fit, it would be padded already in order to fit a regular grid of some kind so to even attempt a rail cipher, I needed a divisible number. I used my Version4 and fit it horizontally and then vertically to a 3×30 grid. A note of caution here, I attempted this first and foremost as an exercise and was only marginally optimistic of a solution. When attempting a deciphering, it is definitely worth the time to try and work with the unaltered ciphertext as much as possible. It has to be a logical progression of steps in and out of the enciphering. If you start making crap up as you go along then odds are pretty good it’s not going to get you anywhere.
The deficit of usable vowels discouraged me from trying further to try variations on the idea. In the form it’s in right now(as the 97 letters or after removing the letters KRYPTOS), K4 does not appear to be a rail cipher. Another searcher might try some of the other grid sizes but it seems this is an unlikely solution method.