Ciphers, Codes & Cryptography

A simple number-letter substitution cipher, combined with fingercounting that was recorded by the Venerable Bede. PDF.

The complete title was "Libro llamado Refugium infirmorum , muy útil y provechoso para todo género de gente, en el cual se contienen muchos avisos espiritual es para socorro de los afligidos enfermos, y para ayudar a bien morir a los que están en lo último de su vida; con un alfabeto de San buenaventu ra para hablar por la mano." (Book called refuge of the sick, very useful and beneficial for all kinds of people, in which is contained much spiritual advice for assistance of distressed sick persons, and for helping those who are at the end of their lives to die well; with Saint Bonaventur e's alphabet to speak by the hand).

It contained a manual alphabet that could be used as a mnemonic, or as a method of manual communicat ion.

Imagine a book written in an unknown alphabet, in an unknown language, at an unknown date and place. Could such a book be read? Could one retrieve the information it contains, if any? This question has baffled historians and scientists alike, in the case of a particular medieval document, known as the Voynich manuscript.