Four Hundred Years of Habsburg Cryptography

I added a section "Four Hundred Years of Habsburg Cryptography" in "Habsburg Codes and Ciphers". It is based on Benedek Láng (2020), "Was it a Sudden Shift in Professionalization? Austrian Cryptology and a Description of the Staatskanzlei Key Collection in the Haus-, Hof- und Staatsarchiv of Vienna", which outlines a collection of nearly 500 manuscript ciphers preserved in the Austrian archives.
I learned of this paper in Nils Kopal & Michelle Waldispühl (2021), "Deciphering three diplomatic letters sent by Maximillian II in 1575". These authors succeeded in cryptanalysis of three letters of Maximilian II (and thereafter found that the key is among the above collection). I also added this cipher in the above article.