If I may, Leon Bat<i>t</i>ista Alberti (with two t's, you have a typo in page <a href="https://vcrypto.tonyo.info/venetian_crypto/website/index.php/palgorithms" rel="nofollow">https://vcrypto.tonyo.info/venetian_crypto/website/index.php...</a> ):<p><a href="https://en.wikipedia.org/wiki/Leon_Battista_Alberti" rel="nofollow">https://en.wikipedia.org/wiki/Leon_Battista_Alberti</a><p>belongs to (early) Renaissance and definitely not to Middle Ages (unless you specify "very, very late" middle ages).<p>He was born in Genoa, lived and worked for long years in Florence and Rome (where he died) and in a number of other cities but has NO connection whatever with Venice.<p>Johannes Trithemius was German and had very little connections with Italy, and not particulalry with Venice.<p>Giovan Bat<i>t</i>ista Bel<i>l</i>aso (also two t's and two l's in the surname) actually published his "La Cifra" book in Venice, although he was from Brescia, there are no evidence of particular connectins with Venice and his other works were published in other cities.<p>Blaise de Vigenère was obviously French, and while he traveled to Italy, he only lived in Rome, again there is no particular connection with Venice.
From around the same period and close by in Northern Italy is the Voynich manuscript. Written in an unknown writing system which has yet to be deciphered.<p><a href="https://en.wikipedia.org/wiki/Voynich_manuscript" rel="nofollow">https://en.wikipedia.org/wiki/Voynich_manuscript</a>