Voynich manuscript — often called The world's most mysterious manuscript has eluded attempts to understand its origin, nature and purpose for centuries. Its text consists of a strange collection of symbols linked together by bizarre, unreadable words surrounding otherworldly illustrations. In a new study, independent researcher and science journalist Mikhail Greshko investigated the hypothesis that the manuscript was compatible with ciphertext, attempting to develop a historically plausible cipher that could reproduce the manuscript's unusual properties.
The Voynich Manuscript, named after the antiquarian Wilfried Voynich, is a small book measuring 23.5 x 16.2 cm and containing approximately 240 pages.
Almost every page of the book contains scientific and botanical drawings in various shades of green, brown, yellow, blue and red.
“The Voynich manuscript parchment was produced in the early fifteenth century (1404-1438), and in its design and illustrated content, the manuscript is reminiscent of books created in the early 1400s in Central Europe, especially in the region around the Alps,” Greshko said.
“There are three main schools of thought regarding the nature of the manuscript:
(i) that it is meaningless gibberish, perhaps designed as glossolalia or as a means of carrying out a medieval scam;
(ii) that it represents an early artificial language or perhaps a written form of an obscure or previously unknown natural language;
(iii) that it represents the ciphertext of a known natural language such as Latin, Italian or German.”
In his new work, Greshko described a cipher that reliably encrypts Latin and Italian texts, like decrypted ciphertexts that immediately repeat many of the properties of the Voynich manuscript.
“Named after the 14th-century Italian word for a card game, the Naibbe cipher is a multi-word homophonic substitution cipher that maps individual letters of Latin or Italian plaintext onto multiple separate lines of Voynich glyphs,” he explained.
“The cipher is designed to be executed using materials available in or around the Alpine region at the beginning of the fifteenth century.”
“It works by matching letters to multiple individual strings of Voynich glyphs, creating words that match an expanded version of the slot grammar seen in the manuscript itself.”
The results show that the Voynich manuscript ciphertext hypothesis remains viable.
“Playing cards are also historically plausible, as they were introduced to Europe in the late fourteenth century through trade with the Mamluk Sultanate,” the researcher said.
“Decks of 52 and 78 playing cards are known in 15th-century Europe, and confirmed records of playing cards in Italy date back to 1377 and represent the Florentine ban on foreign card games. Babya term probably borrowed from Arabic.”
“Playing cards are also famous throughout the Alpine region: such a strong card-making industry was established in Venice at the beginning of the fifteenth century that by 1441 Venetian artisans were already mourning the industry's demise.”
“I have developed two versions of the Naibbe cipher,” he added.
“One uses a 78-card tarocchi (tarot) deck that was created in 15th-century Italy for playing tricky card games.”
“Another variant uses a standard 52-card deck, the basic design of which was developed in the Mamluk Sultanate.”
The very existence of the Naibbe cipher suggests that the Voynich manuscript may be compatible with a Latin or Roman language ciphertext.
“To the best of my knowledge, the Naibbe cipher is the first substitution cipher ever described that offers a systematic explanation of how a substitution cipher could change the properties of Latin, Italian, [or] German into the Voynich manuscript,” Greshko said.
“However, the Naibbe cipher's incomplete replication of the Voynich B properties highlights the difficulty of creating a comprehensive encryption-based model for generating Voynich manuscript text.”
“I hope that the Naibbe cipher will inspire new computational analyzes of both Voynich manuscript-mimicking ciphers and the Voynich manuscript itself—and that someday soon the quiet hum of the six-century Voynich manuscript mystery and the cacophony of a century of analysis will give way to melodic harmony.”
study was published in November 2025 in the magazine Cryptology.
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Mikhail Alekseevich Greshko. Naibbe cipher: a substitution cipher that encrypts Latin and Italian as ciphertext, similar to the Voynich manuscript. Cryptologypublished online November 26, 2025; doi: 10.1080/01611194.2025.2566408
