671.0B+ configurations tested and eliminated

Workbench

Configure a transposition + substitution pipeline and score it against K4’s 24 known crib positions. All computation runs locally in your browser (no data is sent to any server).

Your odds of solving K4 right here (spoiler: astronomical)

This workbench exposes roughly 1035 possible configurations. At 3 per minute, 8 hours a day, 365 days a year, you would finish in about 1028 years (roughly a quintillion universe lifetimes). Bring snacks.

You are 1012× more likely to win the Powerball twice in a row than to stumble on the answer here. And yet, someone, someday, might try an “obvious” keyword that over 35 years of PhDs missed and crack the last unsolved message at CIA headquarters. That’s cryptanalysis.

Over 668 billion configs have been formally eliminated by this project. Only 1035 minus 668 billion to go.

What we know about K4 (research context)

Sanborn stated K4 uses two systems of encipherment. Pure transposition is impossible (CT has 2 E’s, cribs need 3), so at least one layer is substitution. The leading model assumes: plaintext → transposition → substitution → carved text (reverse order not yet ruled out).

Eliminated proven impossible

  • All single-layer substitution on the raw 97 characters (periodic Vigenère/Beaufort/Variant Beaufort, periods 1–26, both AZ and KA alphabets)
  • Pure transposition (CT has 2 E’s, cribs need 3)
  • Columnar transposition × periodic substitution (47M+ configs tested)
  • Null mask + periodic substitution on any 73-char extract (periods 1–23)
  • Autokey on raw 97 (exhaustive single-letter + 1M dictionary keys)

Open territory viable

  • Non-standard transpositions (serpentine, spiral, Myszkowski) + substitution
  • Autokey / running key after undoing transposition
  • Custom or Quagmire tableaux
  • 73-char hypothesis with non-periodic cipher after null removal

Watch for 23/24

K2 ends with an X separator, K3 ends with a stray Q. If K4 has a similar delimiter, one crib position would mismatch even with the correct key, capping the score at 23/24. Also: 73 is prime (no clean grid), but 72 = 8×9, matching Sanborn’s “8 lines.” A 72+1 message with delimiter would give a perfect grid. If you hit 23/24, check which single position missed; it may be the delimiter.

Full methodology and elimination landscape →

Quick presets

Vigenère + KRYPTOS

K1–K3 method eliminated

Beaufort + KA alphabet

Kryptos-keyed Beaufort eliminated

Columnar w=7 + Vig

Two-system model open

Rail fence + Beaufort

Non-standard transposition open

Serpentine + Vig

Boustrophedon reading open

DEFECTOR 15/24

Historic high score disproven

Try your own

Blank slate

K4 Ciphertext

97 characters. Green = known plaintext positions (24 total).
0 Null Mask

73-char hypothesis: 24 of 97 are nulls.

1 Transposition
2 Substitution

Enter a substitution key above to see results.

Session history (0 attempts)

Cipher toolkit inspired by enigmator by Merricx.