The following article is Part 4 of a six-part series on the Kryptos Plaintext discovery. The original free pdf document can be downloaded from https://stephenbishop.org/downloads.
CONSTRUCTING THE UNKNOWN PLAINTEXT
Since the CIA NHB is symmetrically designed with the Berlin Clock shape centered on the building, the unknown plaintext will be constructed with BERLINCLOCK centered within the plaintext.
To center the BERLINCLOCK plaintext, a slide to the left of 20 places is required. The plaintext wraps around to the end. There are still 97 letters. The N in BERLIN is now the center letter. The red “x” is used to track the original K4 Known Plaintext start letter position.
PLAINTEXT 2, SYMMETRICAL K4 KNOWN PLAINTEXT, where the “x”s are unknown letters
Since we have East North East mapped to the building on the new left side (Compass West side), it’s a straight forward process to follow the left side building stair step outline and add new plaintext in a repeating EAST NORTH EAST pattern. The single letters N and E are used to represent NORTH and EAST.
PLAINTEXT 3, PROPOSED SYMMETRICAL K4 PLAINTEXT, Left side
Convince yourself that the correct number of EASTs and NORTHs have been added to agree with the left side of the building stair step pattern.
There remain three unknown letters on the left side designated by “x”s. These will be discussed below.
There are two possibilities for the right side of the plaintext. The first is to write the plaintext in the normal English Left to Right reading direction, in agreement with the released known plaintext.
The building stair step pattern directions are read off with respect to Compass North. In this case, the right side of the plaintext would have an EAST SOUTH EAST repeating pattern. I skipped this image.
PLAINTEXT 4.1, PROPOSED SYMMETRICAL K4 PLAINTEXT, Right side LR reading direction
The second possibility for the right side of the plaintext is to write the plaintext Right to Left. In this case, the right side would have a WEST NORTH WEST repeating pattern in the reversed direction. The single letters N and W are used to represent NORTH and WEST.
PLAINTEXT 4.2, PROPOSED SYMMETRICAL K4 PLAINTEXT, Right side RL reading direction
There remain three unknown letters on the right side designated by “x”s. These will be discussed below.