Ernest Rinzi was a 19th century jeweler, goldsmith and miniaturist. He left behind an encrypted journal that is still unsolved. My first impression is that this journal is the most notable unsolved encrypted book after the Voynich Manuscript and the Rohonc Codex.
The Blitz Ciphers are an encrypted book allegedly found in London just after World War II. Only eight page scans have been published. Some of my readers consider the Blitz Ciphers a fake.
On a Russian website a handwritten notebook from the Soviet era is described. Its content is encrypted. Can a reader solve this unusual cryptogram?
An unknown Freemason author once published a book, the content of which is given as a picture word puzzle (rebus). The solution is not known to me.
My list of encrypted books keeps growing. The latest entry (book number 80) is one of the most peculiar.