Johannes Trithemius
From Grimoire
Student, abbot, occultist, magician -- all these things and more were Johannes Trithemius, but most of all he was a man desperately seeking the truth behind the mysteries of the Liber Juratus.
Finding the original copy of the grimoire in an abbey during a snowstorm, he contrived to become the abbot even though he was only 21, and spent the next 25 years conducting research on the tome -- collecting other copies, comparing notes and translations, and trying desperately to fully reconstruct the medieval book of dark magic. Ultimately, he realized that the deepest secrets would be beyond him, and so he recruited others, including Heinrich Cornelius Agrippa, to pick up the torch and try to solve its secrets.
In his works on cryptography, he betrayed his knowledge of Honorius, the author of the Liber Juratus, by using the Theban Alphabet -- thus creating yet another layer of steganography over his aptly-named Polygraphia.