Voynich manuscript - Analysis of the codification algorithm with the encryption methods known in the medieval time and results of the marginalies that were not encrypted

1. Introduction

In medieval times it was very common to decipher how it was used since ancient times. The most important classical encryption techniques are transposition ciphers which rearrange the order of characters in a message therefore the letters are changed as well as substitution cipher where plaintext are replaced with cipher text. The word 'number' comes from the Hebrew word ' לִסְפּוֹר' as well as 'צוֹפֶן' code, cipher. Cryptographic examples can be found in some Hebrew biblical texts for e.g. 'Tehillim' (Gladyseva, 2019), furthermore as simple monoalphabetic substitution 'Atbash' cipher (500 BC). The Greek historian Polybius invented "Polybius square" cipher, where the letters of the alphabet were arranged left to right, top to bottom in a 5 x 5 squares, but similar squares were already had been used by Jewish scholars (Polybius, [146 a.C]1922).

Different kind of ciphering was used in occult hermetic texts of ancient Greece with cryptographic system based on homophonic substitution, understanding the meaning (Gladyseva, 2019) metaphors with another connotation of the text. The method currently known as César supposedly used by Julio César and known as César encryption or offset encryption.

However, these methods were used in part in the Voynich manuscript, with the method of encryption of different algorithms that was unknown in the medieval period in other manuscripts. Therefore, for more than half a thousand years no one could decipher it.

2. The methods of decoding in the medieval period and their connections with the decryption methods of the investigation of the Voynich manuscript

In the medieval period of Europe encryption was using not only due increased diplomatic activity for convey confidential information, but to conceal information especially in alchemical treatises where symbols were used instead of letters often. The research achievements of the Voynich manuscript indicate that the connotation of its text was influenced by medieval alchemical philosophy (Gladyseva, 2019).

The most important book that describing the use of cryptography in alchemy is the 13th century Roger Bacon's work 'The Message of the Monk Roger Bacon on the secret actions of art and nature and the Nobility of Magic' in Latin 'Epistola Fratris Rog. Baconis, de secretis operibus artis et naturae et null magitate' (1270), which describes the use of 7 methods for hiding a text. According to Roger Bacon: ' A man is a crazy who writes a secret in any other way than one which will conceal it from the vulgar.>'

The most interesting result in the encryption code of the Voynich manuscript that made decryption more complicated over the centuries was the use of polyalphabetic encryption that was used partially and simultaneously with monoalphabetic encryption (Gladyseva, 2019).

But according to the history of encryption, polyalphabetic encryption was invented by Leon Batista Alberti in 1467, who identified the idea of ​​using polyalphabetic encryption: multiple encrypted alphabets with change in a few words, which is why he was called the 'father of Western cryptology'. The present study of the text of the Voynich manuscript and the translated information confirmed the current analysis that it was written after 1467 (Gladyseva, 2019).

The polyalphabetic system, which uses several monoalphabetic figures periodically, alternating between each of the three words. Depending on the position of the internal disk, 24 possible variations are defined. One of the disks of the different alphabet was used to represent the decryption method, and the other was from the alphabet with the numbers 1, 2, 3 and 4 (Hernández Gómez, 2010). But it is important to underline that the polyalphabetic system in Voynich manuscript was used partly (Gladyseva, 2019).

In analysing of the encryption methods that were used in the medieval period and their opposition and equivalence with the coding algorithm of the Voynich manuscript was very useful the first treatise of the medieval period, dedicated exclusively to cryptanalysis, the work of Francesco (Cicco) Simonetta (1410-1480), secretary of Sforza (Simonetta, 1474).

He established thirteen rules for decoding of replacement ciphers, which contain word delimiters. On the basis of his manuscript, the most important:

'… is to find out whether the document is written in Latin or in a local language, and this can be established as follows: find out if the words in this document have only five different endings, less or more …> if there are only five or less, you are justified in concluding that it is in the vernacular; if they are more than five you can assume your document to be in Latin.>' (Simonetta, 1474)

The first Voynich manuscript’s preluminal cryptanalysis of my research yielded results that it was not written in Latin, but in some language or its dialect. This method of decryption was possible only after deciphering some words and the names of the first flowers. (Gladyseva, 2019)

Important notes by Francesco (Cicco) Simonetta on words that consist of one, two or three characters that are repeated more frequently in vernacular than in Latin, where the words represented by a single character are four: 'the prepositions 'e' and 'a', the vocative adverb 'o' and the imperative verb 'i', but these one-letter words are rarely used, except the preposition 'a' (Simonetta, 1474).

Simonetta's thirteenth rule was about double letters that were easy to decipher and was well known in medieval times, therefore, in the Voynich manuscript, double letters were generally omitted (Gladyseva, 2019).

Simonetta's sixteenth rule included a known method of coding when the texts were partly in vernacular and partly in Latin, according to my research, this method was infrequently used in the Voynich manuscript, as well as the character method of text that had no meaning especially in the words of the alchemical lexicon (Gladyseva, 2019).

But the most encrypted text according to Simonetta had been encrypted with two completely different cipher alphabets, which in varying degrees this method was also used in the Voynich manuscript (Gladyseva, 2019). The implementation of the text, based on the binary coding of the letters of the alphabet, was very useful for an encryption. The way to encode two slightly different fonts in clear text was used not only in the Voynich manuscript that was written in the Cistercian monastery in northern Spain, but also by the German Benedictine abbot Trithemius.

A German Benedictine abbot Johannes Trithemius (1462 –1516) wrote the 'Steganographia' (1499) where invented the cipher 'Ave Maria' as well as a cipher built on the basis of a periodically shifted key and 'Polygraphia' (1518) with the 'cipher Trithemia'. He published the ‘tabula recta’ or ‘Trithemia table’ where the first letter of the text is encrypted on the first line, the second letter on the second, and so on, after using the last line, they return to the first line again. It was necessary to order the letters on the first line in an arbitrary order, preserving the cyclic change rule on the following lines that are written with letters of an ordered alphabet.

According to some researchers, for example Gordon Rugg, John Dee (1527 - 1608 or 1609) may have owned the Voynich manuscript, as well as 'The Book of Soyga' of the 16th-century codified Latin treatise on magic he was using. In 1564, Dee wrote the Hermetic work 'Monas Hieroglyphica' ('The Hieroglyphic Monad') that had methods of a secret symbolism as well (Rugg, 2004).

In 1582, he met Edward Kelley, who tried to reveal the Philosopher's Stone, interesting because, in addition, the theme of the Voynich manuscript is about the secret of transmuting base metals into gold (Gladyseva, 2019).

In alchemical treatises, the symbol of the philosopher's stone is a rebis, hermaphrodite, which appears as a result of the combination of the 'king' who is philosophical sulphur and the 'queen' who is philosophical mercury in an alchemical marriage. (Gladyseva, 2019) Therefore, the 'queen' in the Voynich Manuscript is a philosophical mercury, but not the Aragonese queen as Gerard Cheshire of the University of Bristol claims in his articles (Cheshire, 2019).

As mentioned in the manuscript of 'The Five Mystery Books' by Dee, on April 11, 1583 he was able to decipher the scroll that Edward Kelley found in Northwick Hill and codify it in Latin: '... abowt un certayne moniment de un boke y un skroll (escrito en caracteres extraños) fownd en Northwik.>' (Rugg, 2004).

Commensurate with 'Five Books of Mystery', he invented the coded alphabet, curious that the letters 'i'; 'and' or 'gon' also exist in the Voynich manuscript (Gladyseva, 2019).

Fig.1

It was believed by Giambattista della Porta (1535? - 1615) that if the topic of the coded text is known, the analyst can make knowing supposes regarding to words that are commonly used in a special context. In reason, each context is characterized by some common words that are using frequently. The same method of deciphering was successfully used in the Voynich Manuscript (Gladyseva, 2019). Porta invented methodology of deciphering the multi-alphanumeric ciphers. The multi-alphanumeric ciphers are difficult to decipher and sometimes they only succeeded in analysing and finding the correct key. For e.g. the word 'Lavender' in the Voynich Manuscript (Gladyseva, 2019).