Experiment 190
F11.2. The poem code (SOE, Second World War): the agent takes words from a memorised text, writes them out as one key, numbers its letters alphabetically (ties left to right) and transposes twice by columns with that number key. Here the memorised texts are the sculpture's own: the plaintexts of K1, K2 and K3 and the Morse. Keys: every run of 1-6 consecutive words, 5-40 letters; used for both transpositions, or split into two keys at every word boundary. Each move and its inverse, then (A) or before (B) a repeating key 1-26 on 8 table classes (F6's compiled tester); K4 against 15 shuffled copies. 0167-era double columnar tests used dictionary keywords, not these phrases.
What the method does with the 24 known letters.
British agents in the war carried their keys in their heads: a poem. They picked a few words, wrote them out, numbered the letters in alphabetical order, and used the numbers to shuffle the messagethe message The 97 letters of English that Jim Sanborn wrote and enciphered. twice through 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.. Here the 'poem' is the sculpture's own solved text. We try every run of a few consecutive words as the keythe secret word The word or string a cipher needs besides the method., with a repeating secret worda repeating secret word A secret word written under the message again and again. on the sculpture's tables before or after.
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.
SOE agents kept their keys in a memorised poem: a few words written out, their letters numbered alphabetically, used to shuffle the message twice through a grid. The sculpture's solved text is a poem its makers knew by heart.
Every run of 1-6 consecutive words of K1, K2, K3 and the Morse as the key, used twice or split in two, each shuffle undone, then a repeating key of 1-26 on the sculpture's tables before or after; 15 scrambled copies.
Nothing fits K4 better than the copies. F11.2 closed for consecutive words; free picks of words remain untested.
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.
key SHADOWFORCES, column numbers [10, 6, 1, 3, 7, 12, 5, 8, 9, 2, 4, 11]
K4 with the double transposition undone: ZJPADRVTLYWOZEJAESUBCGSGXTOSUNQRTVKULIIAWFDGFJBXUTWPKLGKMKTZALUHKKSKSQUOQPSQWHRONBORBIICNTBFKFWDZ
Family, key space, the constraint under test, and the clues it reads.
C5(b) ('key word/s'), A9 (agency hand systems; Scheidt's CIA background), F11; SOE poem code (Marks, Between Silk and Cyanide). Model: c = T(P2(P1(p))) or P2(P1(T(p))), P1, P2 columnar transpositions keyed by the phrase numbers, T a periodic tableau key. Statistic: 0134's fixed statistic and the shortest live period, K4 against copies.
Written before the run; the result decides it.
No phrase key gives K4 a live period below the copies'; cells where K4 leads stay inside the copies' range. Zero candidates.
The harness's record: candidates, gates, loss, and the negative result this experiment leaves behind.
6092 moves; shortest live K4 A 24 B 25 (copies 22, 25); K4 above every copy in 0 of 52 cells (copies 0-1)
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.