Trithemius in particular stands out for me. His steganography was ingenious, concealed not just behind steganographical techniques, but also by a double veil o

Trithemius in particular stands out for me. His steganography was ingenious, concealed not just behind steganographical techniques, but also by a double veil of taboo and law: it presented itself as demonology, thus pious readers would avoid it altogether, and impious ones would think twice, given the power and reach of the Inquisition. Brilliant!