ma: improve cryptography section

ma/safety_reset.bib

@@ -1497,4 +1497,22 @@
   publisher = {{Heise Online}},
 }
 
+@Article{kerckhoff01,
+  author       = {Auguste Kerckhoff},
+  date         = {1883},
+  journaltitle = {Journal des sciences militaires},
+  title        = {La cryptographie militaire},
+  pages        = {5-38},
+  volume       = {IX},
+}
+
+@Online{kerckhoff02,
+  author   = {Fabien Petitcolas},
+  date     = {2020},
+  title    = {Kerckhoffs' principles from ``La cryptographie militaire''},
+  url      = {https://www.petitcolas.net/kerckhoffs/index.html},
+  language = {English},
+  urldate  = {2020-05-25},
+}
+
 @Comment{jabref-meta: databaseType:biblatex;}