Experiment 108
0023 tested K4 reversed as a whole. Seen from behind the screen, the letters keep their line order but each carved line reads right to left: R K B O, then line 12 backwards, line 13 backwards, line 14 backwards. That order, and the other two mirror readings of the carved block (lines bottom to top, each forwards; and both, the full reversal), are tested with a repeating key of length 1-26 and with ciphertext and plaintext autokey at every lag, the reading before or after the table.
What the method does with the 24 known letters.
The letters of Kryptos are cut right through the copper, so the text can be read from behind, where every line runs right to left. The CIA says 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. of alphabets was flipped on purpose so that it reads properly only from the back. So perhaps K4the carved letters The 97 letters cut into the copper at the CIA, shown at the top of every experiment page. should be read from the back too. We read its four carved lines that way, and in the two other mirror orders, and test the usual short secret words and self-feeding keys against the 24 known lettersthe known letters Sanborn has confirmed that positions 22 to 34 of the message read EASTNORTHEAST and positions 64 to 74 read BERLINCLOCK..
Words in the margin are defined on the glossary page.
The carved letters go in at the top; the reading comes out at the bottom.
The letters of Kryptos are cut right through the copper, and the CIA says the table was flipped on purpose so it reads only from the back. Perhaps K4 is meant to be read from behind too.
Read the four carved lines right to left, or bottom to top, or both, then try a repeating secret word of 1 to 26 letters and the self-feeding keys (autokeys) at every lag against the 24 known letters.
No reading fits a word shorter than 26 letters, and at 26 only as often as scrambled coppers; no autokey survives with three checks. Reading from behind changes nothing.
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.
Redo the method on a few letters with pencil and paper.
The same steps run by the code on the real letters.
K4 on its carved lines and as read from behind:
OBKR RKBO
UOXOGHULBSOLIFBBWFLRVQQPRNGKSSO OSSKGNRPQQVRLFWBBFILOSBLUHGOXOU
TWTQSJQSSEKZZWATJKLUDIAWINFBNYP PYNBFNIWAIDULKJTAWZZKESSQJSQTWT
VTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR RACKEUAUHUKGIDCJTXZKDGWKPFZMTTV
where the known letters sit in the reading from behind:
22->18 23->17 24->16 25->15 64->38 74->90
Family, key space, the constraint under test, and the clues it reads.
Family 4 open item 'mirrored readings beyond reversal' (families.md). The CIA: the tableau 'is intentionally flipped so it can only be read from the back of the sculpture'; the letters are cut through (01-facts.md); Scheidt: 'mirrors and obfuscation' (C13). On the plate K4 fills columns 28-31 of line 11 and lines 12-14 (31 letters each). Routes: (1) each line reversed, order kept (the view from behind); (2) line order reversed, each line forwards; (3) both (= the full reversal of 0023, kept as a check). Keys, with the route either before the table (the message written, read from behind, then enciphered) or after it: periodic key 1-26 in 8 tableau classes (slot agreement); ciphertext autokey at lags 1-96 (each known letter a direct check); plaintext autokey at lags 1-96 (propagated from the known letters to closure); autokey settings count only with 3+ checks. Ten shuffled coppers.
Written before the run; the result decides it.
No reading and key fits: periodic keys dead below period 20, no autokey lag passes all checks, counts inside the coppers' range. Zero candidates.
The harness's record: candidates, gates, loss, and the negative result this experiment leaves behind.
Smallest live period on K4: lines reversed (from behind), read then table: None; lines reversed (from behind), table then read: 26; line order reversed, read then table: None; line order reversed, table then read: None; both (full reversal), read then table: 26; both (full reversal), table then read: 26. Autokey survivors with 3+ checks (lag, class) K4 / controls max: lines reversed (from behind), read then table: CT 0/0, PT 0/0; lines reversed (from behind), table then read: CT 0/0, PT 0/0; line order reversed, read then table: CT 0/0, PT 0/0; line order reversed, table then read: CT 0/0, PT 0/0; both (full reversal), read then table: CT 0/0, PT 0/0; both (full reversal), table then read: CT 0/0, PT 0/0.
What was searched, as the harness recorded it.
How this experiment sits among the others is on the lineage page; its family's open hypotheses are on the families page.