Want to try your hand at some codebreaking? LJS 225, written in Rome between ca. 1455 and 1458 for Pope Callistus III, will teach you how! This manuscript is a work on cryptography that describes two separate systems for creating a deciphering a code. In the first, Italian words beginning with one letter are all represented by Italian words beginning with another letter; in the second, signs or symbols represent letters or entire Italian words.
Fols. 1r-3r are presented here, for the manuscript’s description and further digitized images please see OPenn: http://openn.library.upenn.edu/Data/LJSchoenbergManuscripts/html/ljs225.html