“A running key concealed at the sculpture, joined to a K3-style move before or after it”
0017, 0004, 0021 and 0078 tested running keys from the sculpture's texts, K1-K3, Carter's book and Sanborn's letters with no move. Here each of those keys is joined to every move of the type-1 route library (K3's counting rule, one or two quarter turns, plain and true-keyword column shuffles, 27,000-odd distinct routes), with the move either before the table or after it. A running key leaves no free letter, so both orders are exact tests.
A running keya running key A secret word as long as the message, taken from a book or another text. is a long text used as the secret, one letter of it per letter of the messagethe message The 97 letters of English that Jim Sanborn wrote and enciphered.. The sculpture carries several such texts: the tablethe table The right-hand half of the sculpture, 26 rows of the alphabet each shifted one place further, starting from the word KRYPTOS., the Morse messages, the solved parts. Experiment 17 tried them on K4the carved letters The 97 letters cut into the copper at the CIA, shown at the top of every experiment page. directly. Here the letters are also moved the way K3the earlier messages The three solved parts of the sculpture.'s were, by turning a grida grid Writing the message into rows of some width and reading it out in another order, column by column for instance, which shuffles the letters without changing them. or reading columns, either before or after the table is used. Because a running key has no free letters, each combination either explains all 24 known letters or it does not.
Words in the margin are defined on the glossary page.
1.1
The method at work
The carved letters go in at the top; the reading comes out at the bottom.
the stack
Sanborn said he moved letters about in 'matrixes' and then 'went back to this table'. Here a key text found at the sculpture, read straight along, is joined to a K3-style move, the move done either before or after the table.
the check
A running key leaves no free letter: each of the 24 known letters fixes one letter of the key text, at its own place if the table comes first, at its carved place if the move does.
the bound
The tableau, the Morse, K1-K3, Sanborn's letters and Carter's book, forward and backward at every start, with 27,852 moves: no match, and the deepest run of checks, 7, is what scrambled coppers reach.
2
Best candidate against the known letters
This experiment produced no candidate: the search ruled everything out before a full text was built. Its product is the bounded negative in section 7.
3
Walkthrough, by hand
Redo the method on a few letters with pencil and paper.
Pick a move, say a clockwise quarter turn of a grid 8 letters wide, and a key text, say the Morse as carved.
Change then move: the letter at place 22 of the message ends up at some place j of the copper; read the carved letter there.
Find the key letter that turns E into that carved letter on the sculpture's table.
The key text, started at offset o, must have that letter at its place o + 22. Do this for all 24 known places.
Move then change: first move the message, so E of place 22 lands at place j; the key letter must sit at place o + j and turn E into the carved letter at j.
Slide o over the whole key text and repeat for every move, every key text, both directions and 12 table rules.
the worksheet: the first steps by hand, on squared paper
4
Worked example, generated
The same steps run by the code on the real letters.
(worked_example failed: IndexError('string index out of range'))
5
Hypothesis, for a cryptanalyst
Family, key space, the constraint under test, and the clues it reads.
Types 1 and 3 of directions.md crossed. Scheidt: 'the keys were concealed at the sculpture' (C6(a)), K4 is 'more than one stage'; Sanborn: 'double matrixes and triple matrixes... then went back to this table' (C1); earlier text holds instructions for later text (C7(a)). Key sources, each forward and backward at every cyclic offset: the carved tableau by rows, by rows with the index column and by columns; the Morse as carved and in reverse order; the four ciphertexts as one panel (0017); the K1-K3 plaintexts (0004); Sanborn's 1989 letter, the 1991 dedication texts and the 2025 open letter (0078); Carter's book (0021, change-then-move only). Moves: K3's rule i -> a + b i mod 97 for every a, b; one quarter turn at widths 2-96 either way; two clockwise turns at every pair of widths; plain columnar left-to-right or right-to-left; true-keyword columnar (issue #26) from the puzzle's words; each forward and inverse, deduplicated. 12 conventions (Vigenere, Beaufort, variant Beaufort; key and text numbered on standard or KRYPTOS). Change then move: the forced key at the 24 crib places must equal the source at those places, a dictionary lookup. Move then change: the key places are the moved crib places; offsets are filtered check by check. Exact, all 24 checks; the deepest partial match is compared with ten shuffled coppers.
6
Prediction
Written before the run; the result decides it.
No combination explains all 24 known letters in either order. Change then move: no source matches either whole crib stretch (13 or 11 letters). Move then change: the deepest partial match is 7-8 checks, inside the scrambled-copper range. Zero candidates.
7
Method
Build the key texts and the deduplicated route library.
Change then move: for each route and convention, undo the move at the 24 crib places, compute the key letters forced there, and look them up in an index of every source window with the crib spacing (whole set, and each crib stretch alone).
Move then change: the forced key letters sit at the moved crib places; for each source keep the offsets that agree at the first moved place, then the second, and so on, and record how deep any offset gets.
Repeat both on ten shuffled coppers.
Decrypt and return any full match.
8
Result and bounds
The harness's record: candidates, gates, loss, and the negative result this experiment leaves behind.