Approach	Why dead	Source
Ciphertext autokey, any lag 1-96, any of 24 alphabet/mode conventions	Exact crib check at every position beyond the lag; zero survivors	experiment 0002
Plaintext autokey at lags 1-25 and 30-52	Chained closure from the cribs conflicts under every convention; lags 26-29 force 60 letters of noise	experiments 0003, 0012
Ciphertext or plaintext autokey with keyword-mixed alphabets from the vocabulary	No ciphertext-autokey setting within three mismatches; plaintext-autokey lags 1-24 and 33-49 dead, others noise	experiment 0025
Running key from K1, K2, K3 plaintext or ciphertext, any offset, either direction	165,216 trials, zero survivors	experiment 0004
The same running keys under keyword-mixed alphabets from the vocabulary	146.9 million trials, none within two mismatches	experiment 0045
Carter's book and the sculpture's texts as running keys with one side keyword-mixed	858 million trials, none within two mismatches	experiment 0047
Running key from the carved tableau, the Morse, or the whole right-hand panel, any offset, either direction	162,912 trials, none within three mismatches	experiment 0017
Running key from Carter's Tomb of Tut-ankh-Amen vol. 1, any offset, either direction	13.7 million trials, none within two mismatches	experiment 0021
Periodic tableau with separate alphabets at periods 1-26 and 30-52	Forced key letters conflict under all 24 conventions	experiment 0005
Periodic tableau at surviving periods keyed by a vocabulary word or a K1-K3 phrase	Forced fragments match nothing in the pool	experiment 0005
Columnar transposition (plain, keyed by vocabulary, or double plain) then a periodic tableau with a key shorter than 23	Smallest crib-consistent period over 2,905 routes and 24 conventions is 23	experiment 0006
Periodic tableau with a vocabulary or K1-K3 key of length 26-30, then a columnar transposition from the 0006 route set	Forced fragments match nothing	experiment 0007
K3's transposition rule at any shift, or a double grid rotation, then a periodic tableau with a key shorter than 22	Smallest crib-consistent period over 21,025 routes is 22	experiment 0008
Periodic tableau with a readable key under the standard or KRYPTOS alphabets, exact copper or one letter off	Forced key stretches score as noise under all 24 conventions and all 195 one-letter variants	experiment 0009
Periodic tableau with a readable key, alphabets mixed from any vocabulary word by any Friedman mixing	Best forced stretch equals the shuffled-letter null	experiment 0010
Progressive-key periodic tableau at periods 1-25 and 31-51, any step 0-25, either form	Crib collisions conflict under every step and convention	experiment 0011
Progressive key at periods 1-24, any step 1-25, keyword-mixed alphabets from the vocabulary	Crib collisions conflict under every pair and step	experiment 0042
Gromark-style running numerical key, any two-term lag rule up to 12, base 10 or 26, alphabets built from the vocabulary	The 13 consecutive known shifts obey no such rule	experiment 0013
Two key words of total length 24 or less, composed through two tableau passes, standard or KRYPTOS alphabets	The 24 crib equations are inconsistent for every such pair	experiment 0014
Two key words of total length 21 or less, two passes, keyword-mixed alphabets from the vocabulary	Inconsistent under every alphabet pair; 22-24 survive at chance rates with no word match	experiment 0043
Columnar, K3-rule or double-rotation route, then a periodic tableau with a readable key at periods up to 40	Best forced key scores inside the shuffled-letter distribution	experiment 0016
Any letter-for-symbol substitution over 26 symbols, then any route in the 0016 set	Crib images clash under every route; shuffled K4 gives zero survivors too	experiment 0019
Periodic tableau at periods 1-25 and 27-52 with plain and cipher alphabets mixed from any vocabulary word	Crib collisions conflict for every alphabet pair; survivors at 24-26 match the shuffled control	experiment 0020
Porta on any standard, KRYPTOS or vocabulary-mixed alphabet order	No order separates all 24 crib pairs across the halves	experiment 0022
Reversal, regular nulls or prefix nulls, then a periodic tableau	Smallest live period 26 under every mask; fragments below the shuffled controls	experiment 0023
A word of length 2-25 plus the K2 coordinate digits as an additive second key	Crib equations inconsistent for every reading, alignment and sign	experiment 0024
Two keyed columnar transpositions from vocabulary words, then a periodic tableau with a readable key at periods up to 40	Forced keys inside the shuffled-control range	experiment 0026
Gromark-style running key in any base up to 15, alphabets built from the vocabulary	Every alphabet triple forces a shift of 15 or more somewhere in the cribs	experiment 0028
Ciphertext as its own key at any stride and start; plaintext mirrored as key from any centre	None within five mismatches; every mirror chain breaks	experiment 0030
Grid keyed by row (one key letter per row), widths 2-48, any key length, vocabulary alphabets	Cribs in the same row force different key letters under every alphabet pair	experiment 0032
Trifid with any cube, periods 2-15, any alignment	No cube is consistent with the 24 known letters; solved by constraint propagation	experiment 0040 (0039 errored on its summary line; keyword cubes to period 20: 0033)
Periodic tableau at periods 27-29 under any pair of standard, KRYPTOS or vocabulary-mixed alphabets, any key	The best completion of the key reads as noise, equal to shuffled K4	experiments 0034, 0035, 0048
Hill with chaining (ciphertext or plaintext feedback, summed input) or two alternating matrices, sizes 2-4	Inconsistent on the crib blocks, or the solved matrix breaks the partial-block cribs	experiment 0036
A repeating key, then K3's rule, one or two grid turns or a column shuffle, then a second repeating key, both on the standard or both on the KRYPTOS alphabet, key lengths 2-14 each	No case with five or more independent checks; counts at the scrambled-copper rate	experiment 0080
K3's rule, one or two grid turns or a column shuffle joined to plaintext or ciphertext autokey, either order, any lag, one alphabet throughout	Nothing passes five checks; counts at the scrambled-copper rate	experiment 0081
One or two quarter turns at any widths with the blank cells at the top, or carried as fillers into the second grid, or a short-row-on-top columnar, then or before a periodic key of length 1-26	Nothing live below period 22; 22-26 at the scrambled-copper rate	experiment 0082
Three clockwise quarter turns at any widths 2-96, then or before a periodic key of length 1-26	At the scrambled-copper rate; the one setting live below 21 (period 18) has a non-word key and decrypts to noise	experiment 0083 (exhaustive; 0037 sampled mixed triples)
Double columnar, one stage width 7 in any of the 5,040 orders, the other plain (widths 2-30) or keyed by a puzzle word, either first, then or before a periodic key 1-26	Nothing live below 21; 21-26 at the scrambled-copper rate	experiment 0084
Keyword columnar read in true key order (repeats dropped or whole word), once or twice, from the vocabulary, K1-K3 and C13/C14 words, then or before a periodic key 1-26 or plaintext/ciphertext autokey at any lag	Nothing live below 22; no autokey setting at five checks	experiment 0085 (the earlier inverse reading: 0006-0081, issue #26)
The ? counted as a 98th symbol and sent to the front by a 98-cell grid (any corner, once or twice), K3's rule mod 98 or a seven-column shuffle, then or before a periodic key 1-26 or plaintext/ciphertext autokey	Nothing live below 21, nothing at four checks; three-check counts inflated by repeated landing patterns, chance	experiment 0086
Key = column letter of one word + row letter of a second key on a grid of width 2-48, standard or KRYPTOS alphabet, either sign, with no move or after/before K3's rule, grid turns or columnar	No width fits the copper as carved (width 7 fails 14 checks); after moves at the scrambled-copper rate	experiment 0087
Key = column letter of a word of length 2-31 + a shift that changes every m letters (m 2-50, any offset), including one shift per carved 31-letter line	Nothing with two or more checks consistent	experiment 0088
Three transposition stages from the sampled set, then a periodic tableau with a readable key up to period 40	A 15 percent sample; best forced key equals the shuffled maximum	experiment 0037 (sampled, not exhaustive)
A word of length 2-25 plus any of seventeen dates or counts from the sculpture's story as an additive digit key	Crib equations inconsistent for every reading, alignment and sign	experiment 0038
Spiral, snake or diagonal route at widths 2-48, before a periodic tableau or after a substitution	Chance before; crib images clash after	experiment 0041
Hill 2x2 to 4x4, plain or affine, letters numbered by any vocabulary-mixed alphabet	2x2 and 3x3 inconsistent on the crib blocks; 4x4 solutions break the partial-block cribs	experiment 0044
Gromark-style two- or three-term rule with lags up to 13, any base 16-26, vocabulary alphabets	No rule fits the 13 consecutive known shifts	experiment 0046
A key of length 27-29 shaped from two vocabulary words, a mirror or a doubling, any vocabulary alphabet pair	None within three mismatches of the 24 forced letters	experiment 0049
Two words in two passes on vocabulary alphabets with the copper off by one letter anywhere, total length up to 22	Survivors only at 21-22, at the shuffled-copper rate	experiment 0050
Pure transposition of the carved letters, any route or key	The cribs need three Es; the copper has two	experiment 0051
Playfair, two-square, four-square, bifid 5x5, ADFGX/ADFGVX, any 24- or 25-letter alphabet	K4 uses all 26 letters and has odd length	experiment 0052
Periodic tableau keys on alphabets keyword-mixed from K1-K3 words or the 2025 letter's words, periods 1-52	Only the always-surviving 27-29 and a one-equation artefact at 26/52; no word fits	experiment 0053
Gromark and two-term digit keys in bases up to 16 on K1-K3-word alphabets	Every pair forces a shift of 16 or more	experiment 0054
Hill 2x2 and 3x3, plain or affine, on numberings from K1-K3 words	Inconsistent on the whole crib blocks under all 200 numberings	experiment 0055
Two words in two passes on K1-K3-word alphabets, total length up to 20	No length pair below 21 survives	experiment 0059
The K2 coordinates as a 2x2 or 3x3 Hill matrix	At most 4/24 cribs, below random matrices	experiment 0060
A word plus the misspelt or raised letters (QUA, LOE, YAR, DYAHR) as a second key	Best 8/24 cribs, at the shuffled-copper level	experiment 0061
Columnar transposition (single, keyed, double) before or after ciphertext autokey, lags 1-95	No route, lag and convention reproduces the cribs; best 9/24	experiment 0063
Ciphertext autokey on K1-K3-word alphabets, lags 1-95	Never within two mismatches; shuffles do as well	experiment 0064
Ciphertext autokey at any lag plus a periodic key of any period, standard or KRYPTOS alphabets, any sign	No case with three or more redundant checks survives; one- and two-check survivors at the shuffled-copper rate	experiment 0066
Two-lag ciphertext feedback (sum or difference of the carved letters a and b back), any lags up to 74, plus a periodic key up to 30, standard or KRYPTOS alphabets	Survivors at the shuffled-copper rate, scattered; distances 1 and 21 never with more than one check	experiment 0067
Ciphertext autokey at any lag, constant shift allowed, with one carved letter wrong, missing or extra anywhere	No variant passes three checks; survivors at the shuffled-copper rate; lag 21 none	experiment 0068
Gromark base 10, any two-term rule with lags up to 6, any primer, any mixed alphabet, four forms	No primer gives an alphabet consistent with the 24 known letters	experiment 0069
Every block of seven reshuffled by one fixed order (5,040 orders), before or after a periodic tableau, periods up to 26	Periods up to 24 dead; 25 and 26 survive at the shuffled-copper rate; no word in the forced fragments	experiment 0070
Periodic key or ciphertext autokey on any alphabet one swap or one move from KRYPTOS (925), with itself or the standard alphabet	Periods up to 25 dead, 26 at chance, no word in 16,671 fragments; autokey at the shuffled-copper rate	experiment 0071
Periodic key, ciphertext autokey, or both, on alphabets keyword-mixed from the 32 compass points and the 2025 letter's words	At the shuffled-copper rate; no word in 10,671 fragments	experiment 0072
Plaintext autokey plus a periodic key, any lag with known pairs, periods 1-96, standard, KRYPTOS or 161 word alphabets	No survivor beyond four nested coincidences at three checks; none at four	experiment 0073
Affine (decimated-alphabet, Atbash-type) masks on the standard or KRYPTOS alphabet, before or after a periodic key or ciphertext autokey	Periods up to 25 dead, 26 and autokey at the shuffled-copper rate, no word	experiment 0074
The doublets as nulls or fillers: the three inside the cribs on structure, BB, SS (43-44) and ZZ struck out in any combination before a periodic key or ciphertext autokey	Inside-crib doublets carry different known letters; struck-out combinations at the shuffled-copper rate	experiment 0075
Gromark with a free mixed alphabet in bases 2-9, 11-16 (lags up to 5) and 26 (lags up to 4), any primer, four forms	No primer gives a consistent alphabet	experiment 0076
A fixed reshuffle of every block of seven (5,040 orders), before or after ciphertext autokey at any lag	Survivors at the shuffled-copper rate; none with four checks; lag 21 never three	experiment 0077
Running key from Sanborn's 1989 letter to CIA staff, the 1991 Cryptogram dedication pages, or his 2025 open letter, any offset, either direction	Best 15 mismatches of 24, the same as shuffled coppers	experiment 0078
Key schedules from the Berlin set-theory clock (lamp counts, hour, minute, time digits) advancing a fixed number of minutes per letter from any start	Best 8 of 24 residuals agree, the same as shuffled coppers	experiment 0079
Monoalphabetic substitution	Same ciphertext letter maps to different plaintext letters in the cribs	cribs
Pure transposition, any route	Cribs need three E's, K4 has two; letter mismatch at fixed positions	cribs
Rotor machines (Enigma class)	K encrypts to K at 74, S to S at 33	cribs
Single-alphabet periodic additive at periods 1-26, 30-52	Crib consistency sweep	kryptos/cribsweep.py
Plain Vigenere with an English keyword under the tableau	Implied key fragments are gibberish under every convention	Schridde 2017; sweep
Hill 2x2, 3x3, 4x4, plain or affine, four numberings, any alignment, either direction	Crib blocks inconsistent, or the solved matrix singular, or partial-block crib letters broken	experiment 0015 (2x2 also Edkins 2004, Bean 2018)
Playfair, either alignment	Doubled ciphertext digraphs SS, TT, QQ are impossible in Playfair	ciphertext
Gromark base-10 length-5 primers	Exhausted (99,999 primers)	Bean 2021
Wichmann-Hill seeds 0-50	Exhausted	Schridde 2017
Mengenlehreuhr (base-5 Berlin Clock) as key schedule	Sanborn named the Weltzeituhr in 2025; eleven community years spent	Scientific American 2025