Steganographia

History

Johannes Trithemius, abbot of Sponheim, wrote the Steganographia about 1499–1500. A letter of 1499 announcing its marvels circulated; Bovillus, who saw the book in 1504, called it demonic in print in 1510, and when it was printed at Frankfurt in 1606 it went on the Index (1609). Books I and II read as conjurations of spirits; W. E. Heidel published a solution of every one in 1676. Book III, unfinished, sets out tables of numbers for the angels of the planets and was taken for astral magic until Thomas Ernst (1996) and Jim Reeds (1998) found messages in it.

How it works

In Books I and II each chapter’s conjuration, read by the general key — the first and last words dropped, every other word joined, every second letter taken — states the rule by which the chapter’s letters hide German and Latin: the initials of every other word, of every third, read backwards, or, in Book II, moved some places along an alphabet of 22 letters. In Book III each spirit has an alphabet of 25 numbers running down from a; a number of 25 or less divides the words.

How it was checked

Every conjuration and letter of Books I and II was transcribed from the 1606 print and is decoded by the tool’s code in the tests: 107 of 110 conjurations and 54 of 59 letters read as Heidel or the Clavis reads them, spellings folded or with letters after the message, most after corrections his text supplies — word divisions, turned letters, a missing clause. All eight tables of Book III, 697 numbers, decrypt to Reeds’s and Ernst’s readings; the differences are misprints of 1606, three of them also in a manuscript.

Limits

The 1606 print gives the hidden text of only one letter; the others are compared with Heidel’s readings of 1676 and the Clavis’s, and no manuscript was consulted. Of the Clavis’s own examples only the four that decode in full are shown. In Book III one word of the zodiac table stays as the prints have it: Ernst’s “umrebs” needs a letter they lack. The ending of Table D is only in the manuscripts.