Experiment 120

“The two key lengths a free alphabet survives (Beaufort form, 23 and 26): climb the alphabet toward English with the 24 known letters fixed, against scrambled coppers at equal effort”

F1.1, second step (English climb). 0119 left one unknown alphabet on both sides alive only in the Beaufort form at key lengths 23 (7 checks) and 26 (1 check). Consistency cannot decide those, so here the alphabet and the free key values are climbed by simulated annealing toward English on the 73 unknown letters, with the 24 known letters held by a penalty that must reach zero. The same climb, same effort, runs on 12 scrambled coppers per length that also fit at that length (drawn by 0119's exact test), and on 6 planted English texts per length to measure power.

revertedstatus
experiment 119parents
28 mintime, all phases
2candidates
24/24known letters
1

The experiment method

What the method does with the 24 known letters.

The last experiment showed that with one scrambled alphabet on both sides of 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., only two key lengths, 23 and 26, can produce 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. at all, and only with the table used the BeaufortVigenere The three rules of arithmetic a table can use: add the key letter to the message letter, subtract the message letter from the key letter, or subtract the key letter from the message letter. way (key minus letter). For those two lengths we now let a computer shuffle the alphabet and the keythe secret word The word or string a cipher needs besides the method. bit by bit, keeping the known letters right, and push the other 73 letters toward English. A climb like this always makes some English-looking fragments, so the same climb is run on scrambled copies of the carved textthe carved letters The 97 letters cut into the copper at the CIA, shown at the top of every experiment page.; K4 only counts if it does better than all of them. To know whether the climb could find a real answer, we also hide real English under random alphabets and see whether the climb digs it out.

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.

OBKRUOXOGHULBSOLIFBBWEASTNORTHEASTOTWTQSJQSSEKZZWATJKLUDIAWINFBBERLINCLOCKWGDKZXTJCDIGKUHUAUEKCARIN: THE COPPER, ALL 97 LETTERS, THE 24 KNOWN PLACES IN ACCENTthe only settings 0119 left: one unknown alphabet, Beaufort form, key length 23 or 26; the alphabet and free key values climbed toward English, the 24 known letters heldbest English score of the 73 unknown letters (higher is more English); 20 restarts x 200,000 moves for every textkey length 23-6.0-5.5-5.0-4.5-4.0K4 -5.81plants above every copper: 3 of 6key length 26-6.0-5.5-5.0-4.5-4.0K4 -5.29plants above every copper: 1 of 612 scrambled coppershidden English, best the climb foundits true scorethe climb never got a hidden English text back (32-43 of 97 letters right, 24 of them given): it has little power hereOUT: K4'S BEST AT LENGTH 23, INSIDE THE COPPERS' RANGE; OVERFITTED FRAGMENTS, NOT A READINGWRYZNNIPNMUPTOMEORJZEEASTNORTHEASTRBYEASILETFIPLSNGESMUCHASTDCEBERLINCLOCKHASANDWLANDWOHLUCEKSENP
the idea

0119 left one scrambled alphabet alive only in the Beaufort form at key lengths 23 and 26. Consistency cannot decide those, so the alphabet is climbed toward English with the known letters held.

the check

The same climb, same effort, on 12 scrambled coppers per length. K4 scores -5.81 at 23 (coppers -5.90 to -5.45) and -5.29 at 26 (-5.33 to -5.01): inside the range both times, low at 23.

the bound

Hidden English beat every copper in 3 of 6 trials at 23 and 1 of 6 at 26, and was never recovered. At 23 the test is weak; at 26, with one check, it cannot decide.

2

Best candidate against the known letters

Laid out as the copper carries K4: OBKR ends the line that finishes K3, then three lines of 31. Left, as carved, the 24 known places in accent. Right, the candidate: a known place it gets right is an accent cell, one it misses is outlined. This is the candidate with most known letters right; none passed every gate.

in: the copper, always the same

as carved, 97 letters; the 24 known places in accent
ECDMRIPFEIMEHNLSSTTRTVDOHW?OBKR
UOXOGHULBSOLIFBBWFLRVQQPRNGKSSO
TWTQSJQSSEKZZWATJKLUDIAWINFBNYP
VTTMZFPKWGDKZXTJCDIGKUHUAUEKCAR

OBKR ends the line that finishes K3, then three lines of 31

out: the candidate

every place read; known places in accent, misses outlined
ECDMRIPFEIMEHNLSSTTRTVDOHW?WRYZ
NNIPNMUPTOMEORJZEEASTNORTHEASTR
BYEASILETFIPLSNGESMUCHASTDCEBER
LINCLOCKHASANDWLANDWOHLUCEKSENP

checked: the known letters in place, and the reading turns back into the copper

3

How the score is made

The loss of the best candidate, part by part. Zero is solved.

Known letters missed0 of 24, ten points each0.00
Englishthe 73 free letters score -5.81; English text scores -3.62.21
Key198 bits to write it down (key words are cheap, arbitrary letters 4.7 bits each); each 60 beyond 60 costs a point2.31
Lossof 240, the worst possible4.52 1.9%
4

Walkthrough, by hand

Redo the method on a few letters with pencil and paper.

  1. Take key length 23 and write K4 in rows of 23, so each column is one key slot.
  2. Guess an order for the alphabet (26 letters in some sequence) and number its places 0-25.
  3. In a column holding a known letter, the key value is (place of the carved letter + place of the known letter) mod 26; every known letter in that column must give the same value.
  4. In the six columns with no known letter, guess a key value.
  5. Decipher every letter: known-letter place = key value minus carved-letter place, mod 26, read back through the alphabet.
  6. Score the 73 unknown letters by how English their four-letter groups are.
  7. Swap two letters of the alphabet or change one free key value; keep the change if the score improves (sometimes even if not, less often as the search cools); repeat many thousands of times.
  8. Do exactly the same with scrambled copies of K4 and with hidden English, and compare the best scores.
the worksheet: the first steps by hand, on squared paper
LENGTH 23, BEAUFORT FORM; K4'S BEST CLIMBED ALPHABET JCRBOQYZPXVWHSMGAUKNFTIELDplacecolumncarvedits placeknownits placesum mod 26key value2221F20E2317172322L24A161414240R2S1315156417N19B322226518Y6E23336821T21I2217176922T21N191414Places 22 and 68 share column 21, places 23 and 69 column 22: the sums must agree, and do. Every other letteris then deciphered as key value minus carved place, read back through the alphabet.This alphabet gives English score -5.81; scrambled coppers reach -5.90 to -5.45 with the same climb.
5

Worked example, generated

The same steps run by the code on the real letters.

key length 23, Beaufort form: K4 in rows of 23; each column is one key slot

  O B K R U O X O G H U L B S O L I F B B W F L
  R V Q Q P R N G K S S O T W T Q S J Q S S E K
  Z Z W A T J K L U D I A W I N F B N Y P V T T
  M Z F P K W G D K Z X T J C D I G K U H U A U
  E K C A R

columns holding two known letters (each gives one check: place(c1)+place(p1) = place(c2)+place(p2)):
  column 0: S under R (24), C under M (70)
  column 1: T under V (25), L under Z (71)
  column 2: N under Q (26), O under F (72)
  column 3: O under Q (27), C under P (73)
  column 4: R under P (28), K under K (74)
  column 21: E under F (22), I under T (68)
  column 22: A under L (23), N under T (69)

best climbed alphabet: JCRBOQYZPXVWHSMGAUKNFTIELD
key values: [15, 5, 24, 9, 10, 23, 5, 12, 8, 0, 8, 6, 24, 17, 18, 21, 0, 22, 3, 10, 8, 17, 14]
place 22: carved F at 20, key 17: 17 - 20 = 23 -> E
6

Hypothesis, for a cryptanalyst

Family, key space, the constraint under test, and the clues it reads.

C27(c) (a tableau 'slightly different from the one on Kryptos'), C1(b) (the table alone). Model: one unknown bijection A on both sides, key k of length L in {23, 26}, Beaufort form A(c_i) = k[i mod L] - A(p_i) (decryption p_i = A^-1(k[i mod L] - A(c_i))); the 0119 exact test shows only these two (form, length) pairs admit any alphabet for 1-26. Given A, the key at every slot holding a known letter is forced (majority value; disagreements are violations); the remaining slots (6 at 23, 3 at 26) are free. Search: simulated annealing over A (swap two letters' places) and the free key values, objective = mean log10 quadgram score of the 73 non-crib letters (the harness's english_score of free_text) minus 1.0 per violation, linear cooling from 0.05 to 0.002, 20 restarts of 200,000 moves; only zero-violation states count. These settings were chosen in dry runs on planted texts before the run (penalty 0.4 and hotter schedules did worse); in those dry runs no setting got a planted text back, and the climb could not even return to the true alphabet from two swaps away, because one swap changes letters in every slot and the forced key values with them. Controls: shuffles of K4 that fit exactly at the same length and form (0119's decider), 12 per length, same restarts and iterations. Power: 6 planted texts per length, 97-letter windows of Carter's Tomb of Tut-ankh-Amen vol. 1 (knowledge/sources) with EASTNORTHEAST and BERLINCLOCK written in at 22 and 64, enciphered under a random alphabet and key of that length; a plant counts as found when the climb's best scores above every copper at that length. A key from such a climb costs about 88 bits for the alphabet plus 4.7 per key letter.

7

Prediction

Written before the run; the result decides it.

Power: the climb finds at least 4 of 6 planted texts at length 23 (best score above every copper) and at least 3 of 6 at 26. K4: its best zero-violation score lies inside the range of the 12 coppers at both lengths, so F1.1 closes as sampled at stated power. If plants are found in fewer than half the trials at a length, that length is recorded as not decidable by this climb and the item stays open there. A K4 score above every copper stops the queue for a replication against fresh coppers.

8

Method

  1. Draw 12 shuffles of K4 that fit at length 23 in the Beaufort form and 12 that fit at 26 (exact test from 0119).
  2. Build 6 planted texts per length from Carter's English.
  3. For K4, each copper and each plant, run the same annealing climb (restarts x iterations fixed in the bounds) over the alphabet and the free key values, the known letters held by a penalty.
  4. Keep the best zero-violation English score per text.
  5. Compare K4 with the coppers per length; report the plants found and how many of their letters the climb got right.
9

Result and bounds

The harness's record: candidates, gates, loss, and the negative result this experiment leaves behind.

2candidates returned
0passed every gate
24/24known letters, best
1.8%lowest loss
nonechampion before

All 2 candidates, lowest loss first.

1failed at baseline24/24 known lettersloss 1.8%
ECDMRIPFEIMEHNLSSTTRTVDOHW?QBHE
FEULCLATLYEPHUVALEASTNORTHEASTP
OILTYNESTUCOOTEVELHOURKMRTISBER
LINCLOCKTBYINAROMTHEENEIGNORGHF

Beaufort form, one alphabet NDPEAFCIXWRMUHGYZKOBTJVSQL on both sides, key length 26

2failed at baseline24/24 known lettersloss 1.9%
ECDMRIPFEIMEHNLSSTTRTVDOHW?WRYZ
NNIPNMUPTOMEORJZEEASTNORTHEASTR
BYEASILETFIPLSNGESMUCHASTDCEBER
LINCLOCKHASANDWLANDWOHLUCEKSENP

Beaufort form, one alphabet JCRBOQYZPXVWHSMGAUKNFTIELD on both sides, key length 23

L23: K4 -5.811, coppers -5.899 to -5.446, plants found 3/6 (letters right [37, 41, 34, 34, 32, 36]); L26: K4 -5.289, coppers -5.326 to -5.008, plants found 1/6 (letters right [29, 37, 38, 38, 43, 36])

What was searched, as the harness recorded it.

family
one unknown alphabet on both sides, Beaufort form, periodic key 23 or 26, no move (the only pairs 0119 left)
search
simulated annealing, 20 restarts x 200,000 moves per text, penalty 1.0 per known-letter violation, T 0.05->0.002
not exhaustive
yes
coppers per length
12
plants per length
6
summary
23
k4
-5.811
coppers min
-5.899
coppers max
-5.446
k4 above all coppers
no
plants found
3
plants letters right
37, 41, 34, 34, 32, 36
plants scores
-5.5, -5.503, -5.455, -5.383, -5.364, -5.295
plants true scores
-4.351, -4.067, -4.379, -4.165, -4.053, -4.013
26
k4
-5.289
coppers min
-5.326
coppers max
-5.008
k4 above all coppers
no
plants found
1
plants letters right
29, 37, 38, 38, 43, 36
plants scores
-5.052, -5.096, -5.075, -5.227, -4.794, -5.092
plants true scores
-4.271, -4.325, -4.075, -4.12, -4.089, -4.351
coppers scores
23
-5.729, -5.815, -5.729, -5.713, -5.446, -5.611, -5.54, -5.702, -5.899, -5.812, -5.671, -5.757
26
-5.118, -5.008, -5.326, -5.264, -5.218, -5.029, -5.104, -5.065, -5.108, -5.161, -5.228, -5.211
k4 best
23
score
-5.811
plaintext
WRYZNNIPNMUPTOMEORJZEEASTNORTHEASTRBYEASILETFIPLSNGESMUCHASTDCEBERLINCLOCKHASANDWLANDWOHLUCEKSENP
alphabet
JCRBOQYZPXVWHSMGAUKNFTIELD
key
15, 5, 24, 9, 10, 23, 5, 12, 8, 0, 8, 6, 24, 17, 18, 21, 0, 22, 3, 10, 8, 17, 14
26
score
-5.289
plaintext
QBHEFEULCLATLYEPHUVALEASTNORTHEASTPOILTYNESTUCOOTEVELHOURKMRTISBERLINCLOCKTBYINAROMTHEENEIGNORGHF
alphabet
NDPEAFCIXWRMUHGYZKOBTJVSQL
key
16, 12, 4, 13, 17, 21, 20, 17, 20, 12, 16, 19, 18, 12, 21, 1, 20, 17, 15, 23, 8, 8, 3, 7, 16, 24
controls
12 shuffled coppers per length that fit exactly at that length and form (seed 120), identical climb

How this experiment sits among the others is on the lineage page; its family's open hypotheses are on the families page.

Rendered from the record on 2026-10-18 12:26 UTC; updated after every experiment.
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