Voynich manuscript
An illustrated parchment codex written in an undeciphered script, probably in the early 15th century and now held at Yale University.
Voynichese: The writing system and text found in the Voynich manuscript, whose underlying language and encoding remain unknown. Its recurring word patterns fuel debate over whether the text encodes language or imitates it.
Voynich manuscript botanical section: A section of the Voynich manuscript containing drawings of plants alongside blocks of undeciphered text. Its often-unidentified plants have inspired proposals about herbal knowledge and invented imagery.
Radiocarbon dating of the Voynich manuscript: Radiocarbon tests that place the Voynich manuscript's parchment in the early fifteenth century. The dating provides a material constraint independent of attempts to read the script.
Parchment: A writing material made from prepared animal skin, used for manuscripts and documents. The codex's parchment enabled scientific dating and distinguishes its physical substrate from its ink.
William F. Friedman: An American cryptologist who led a wartime cryptanalysis organization and studied the Voynich manuscript with other codebreakers. His group brought professional cryptanalytic methods to the manuscript without producing a accepted decipherment.
Cryptanalysis: The analysis of encoded or concealed messages to recover their meaning or determine how they were produced. Attempts to decipher the manuscript apply techniques developed for encrypted texts.
Voynich manuscript astronomical section: A section of the Voynich manuscript with circular diagrams, stars, and other celestial imagery. Its zodiac-like diagrams suggest astronomical or astrological interests without identifying the text's subject.
Rudolf II, Holy Roman Emperor: Holy Roman Emperor from 1576 to 1612, known for his court's interest in art, science, and esoteric subjects. A later account says the manuscript was sold to Rudolf II, though the story is not independently confirmed.
Codex: A book made of bound pages, as distinct from a scroll. Its bound leaves make the manuscript a codex whose page order and gatherings can be studied.
National Security Agency: A United States intelligence agency responsible for signals intelligence and information assurance. Cryptologists associated with its predecessor examined the manuscript as a possible cipher.