LJS 51 Collection of alphabets and encoded correspondence

[Mark Knowles]

That's interesting, what makes the Milanese ciphers more advanced? I was under the assumption Arabic ciphers were more advanced in general, but I must admit I probably read that somewhere and just took it on face value. 

I would think some advancements were probably just natural, I can imagine someone solving ciphers often and realising they need to hide their vowels better to make their ciphers stronger, but are there examples of more complex ideas popping up in both sets of known ciphers around the same time?

This thread should give some context:>

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There is a big difference in the sophistication of diplomatic ciphers between end of the 14th century and the middle of the 15th century. On the basis of all the evidence that I or anyone else to my knowledge has seen this increase in sophistication was very much lead by the Chancellery of the Duchy of Milan, most likely during the reign of Filippo Maria Visconti.