(01-04-2020, 05:09 PM)Mark Knowles wrote: You are not allowed to view links. Register or Login to view.To me it seems much easier to imagine a cipher influenced by the most advanced cipher techniques of the time rather than a complex cipher with no contemporary parallels or influences. So if someone says that the Voynich can't be related in any way to ciphers of the time it seems likely that it is not a cipher.
Many new cipher concepts were added in the 16th and 17th centuries (and since then, of course), so it's not impossible that a new idea or two existed in the 15th century.
Have you looked at the Jewish ciphers? They had some before the 15th century that were different from the usual one-to-one substitution ciphers that were prevalent in the 15th century. Some of them are similar to magic square diagrams (that's a very rough analogy because they are not palindromic, they are alphabetic), but with multiple letters in some of the compartments.