Entropy Analysis of Questionable Text Sources by Example of the Voynich Manuscript

Abstract

The Voynich Manuscript (referred to as ‘VMS’) can be considered as one of the oldest puzzles which remained unsolved until now. While some say VMS is genuine, others say that it is just a hoax. In this research, we propose three methods to analyze VMS and verify the effectiveness of them. The reason for using this manuscript is that no one on this planet knows the meaning of the text of VMS, so we can tackle research without being biased. We analyze from the viewpoint of character frequency and entropy of VMS. Statistical analysis of word frequency already exists, in contrast, we adopt analysis based on a character unit. In that respect, there is diversity from other research. We stated the following three hypotheses as H1 through H3. H1: VMS is a Ciphertext. H2: VMS is close to a programming language. H3: VMS is close to a natural language. The experimental results demonstrate that our methods are valid and efficient. The methods can be applied to all text sources and different classes of them can be distinguished. The possibility that VMS is likely a Ciphertext can be rejected. This mysterious manuscript can be concluded as a meaningful human art, not a hoax. Moreover, the VMS is not encrypted. (However, we are not able to exclude being encoded.)