How to read the archive§
Each card identifies the kind of evidence, links to a source, and states what would have to be shown before a proposed reading should be treated as established. That matters especially for tiny cryptograms, where a name or phrase can be fitted after the fact. For the active Kryptos challenges, see the separate Kryptos research explorer.
D’Agapeyeff Cipher§
1939
Alexander D’Agapeyeff published this 395-digit exercise in the first edition of Codes and Ciphers. No plaintext or method has been verified; a construction or transcription error remains possible.
Verification boundary: An English-looking fragment is not a solution without an exact, reproducible construction for the published digits.
Zodiac Z13§
1970
This short cipher follows the phrase “My name is—” in a Zodiac letter. Its length leaves too little information to distinguish a proposed name from other fitting candidates, and no definitive solution is accepted.
Verification boundary: Treat proposed names as hypotheses, not identifications, unless a method supplies unique and independently checkable validation.
Zodiac Z32§
1970
This 32-symbol message accompanied a San Francisco Bay Area map and was said to concern a bomb location. It has not been definitively decoded; map context does not by itself turn a candidate reading into proof.
Verification boundary: A credible solution must account for the full symbol sequence and produce a falsifiable connection to the accompanying map.
Dorabella Cipher§
1897
Composer Edward Elgar’s note to Dora Penny uses a small set of curved glyphs. Textual and musical interpretations have been proposed, but no reading has gained consensus as the intended message.
Verification boundary: The short text admits many plausible readings; historical fit and an exact, consistently applied key are required before calling one a solution.
Beale Ciphers 1 & 3§
Published 1885
Of the three number ciphers in the Beale Papers, only cipher 2 has a demonstrated Declaration of Independence key. The location and heir messages, ciphers 1 and 3, remain open—and the underlying treasure story itself is unverified.
Verification boundary: The archive separates the unsolved texts from the historical claim: a decryption would not by itself authenticate the treasure narrative.
Voynich Manuscript§
15th–16th century
Beinecke MS 408 is written in an unidentified script by an unknown author. It is not established that the writing is a cipher at all; cryptographic approaches have not produced an accepted decipherment.
Verification boundary: This belongs in an undeciphered-script archive, not in a list of solved cipher systems. Yale provides high-resolution research images.
Phaistos Disc§
Bronze Age Crete
The unique spiral object bears more than 240 stamped signs. Its script, language, purpose, and even whether it should be treated as ordinary text remain unresolved because there is no comparable corpus or bilingual key.
Verification boundary: Proposed readings are not established decipherments. The archive labels it an undeciphered object rather than assuming a specific cipher mechanism.
What is not a solution§
A readable fragment, a favorable n-gram score, a thematic story, or a coincidence with a map or historical event is evidence to investigate—not a decipherment. A strong solution gives a complete method, applies it consistently to the source, and leaves a result that another researcher can reproduce.
Frequently asked questions§
Does unsolved mean nobody has proposed an answer?
No. Many of these objects have many proposed readings. Here, unsolved means there is no generally accepted, reproducible decipherment that explains the full source material without arbitrary choices.
Are all of these conventional ciphers?
No. The D’Agapeyeff and Zodiac entries are ciphertext challenges; the Voynich Manuscript and Phaistos Disc are undeciphered written objects. The distinction is stated on every card because it changes what a valid solution would look like.
Why are short cryptograms especially difficult?
Short text provides too little redundancy to choose uniquely among keys and plaintexts. A candidate can look meaningful while many different candidates fit equally well. Independent verification is essential.