Hall XII · Open Problems · Living Research

Unsolved Ciphers

Nine open problems still under active study by living researchers including Elonka Dunin, George Lasry, and multidisciplinary cryptanalytic teams.

"Every solved cipher started as an unsolved one. The Phaistos Disc has been waiting since 1900. Kryptos K4 has been waiting since 1990. The Voynich Manuscript has been waiting since 1404 (carbon-dated)."

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This hall replaces the old "Unbreakable Codes" framing. The exhibits collected here are not unbreakable — they are unbroken. Some may yield to better statistical models or new evidence (Copiale fell in 2011; Chaocipher in 2010 after 90 years). Others may be hoaxes, false trails, or genuinely undecipherable noise. The museum takes no position. Each exhibit reports the current state of evidence and links the major published attempts.

XII · 1 Voynich Manuscript Carbon-dated to ~1404-1438. 240 pages of unknown script + botanical, astrological, and "biological" illustrations. Over a century of resistance. ~1404 CE XII · 2 Kryptos (K4) Sculpture by Jim Sanborn at CIA HQ, Langley. K1-K3 solved by 1999. K4's 97 characters remain open since 1990. Sanborn has released four cribs. 1990 XII · 3 Beale Ciphers (1 & 3) Three ciphertexts published 1885 supposedly locating buried treasure in Bedford County, Virginia. Cipher 2 was solved with the Declaration of Independence; 1 and 3 remain unsolved. 1822-1885 XII · 4 Dorabella Cipher 87 squiggles sent by composer Edward Elgar to Dora Penny in 1897. No verified plaintext, despite intense scrutiny. Likely a private code or a test of Elgar's known love for cipher games. 1897 XII · 5 Zodiac Z-13 & Z-32 Of the four ciphers sent by the Zodiac killer, Z-408 (1969) was solved within a week and Z-340 in December 2020. Z-13 (his name?) and Z-32 (a location?) remain open. 1969-1970 XII · 6 Shugborough Inscription Eight-letter sequence "O U O S V A V V" carved on the 1748 Shepherd's Monument at Shugborough Hall, Staffordshire. Decoders have included Charles Darwin, Charles Dickens, and modern cryptographers. ~1748 XII · 7 D'Agapeyeff Challenge Cryptographer Alexander D'Agapeyeff's "challenge cipher" published in his 1939 textbook Codes and Ciphers. He removed it from later editions, admitting he had forgotten how to solve it. Open since. 1939 XII · 8 Somerton Man (Tamám Shud) Body of unknown man found on Somerton Beach, Adelaide, December 1948. A torn page reading "Tamám Shud" was sewn into his pocket. A book of 50 letters discovered nearby has resisted decipherment. 1948 XII · 9 McCormick Notes Two notes found in murder victim Ricky McCormick's pocket in St. Louis, 1999. Released by the FBI in 2011 with a public appeal — "the FBI's most baffling cryptanalysis problem". Still open. ~1999 XII · 10 Phaistos Disc A baked clay disc, ~1700 BCE, discovered in the Minoan palace of Phaistos in 1908. Stamped with 241 tokens drawn from a 45-glyph syllabary. The world's oldest unread script. ~1700 BCE

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How an "unsolved" exhibit can become a "solved" one. The path runs through one or more of: (a) statistical attack — Lasry's HMM solution of Z-340 in 2020; (b) computational search — the Beáta Megyesi team's 2011 reconstruction of the Copiale cipher key; (c) archival discovery — a key, plaintext, or contemporary commentary surfaces; (d) cross-disciplinary linguistics — Champollion's 1822 Egyptian decipherment is the model. Every exhibit on this page is open to all four routes.

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