Cryptography & the Occult
6 texts · 12 editions
Cryptographic, hermetic, demonological, and angelological works. Includes the Polygraphia treatises, the Clavis works, the Sigilla, and the Liber Octo Quaestionum (responses to Maximilian on witchcraft).
Works in Cryptography & the Occult
Liber Octo Quaestionum ad Maximilianum Caesarem
A Book of Eight Questions to Emperor Maximilian · 1515first English
Liber Octo Quaestionum ad Maximilianum Caesarem — "A Book of Eight Questions to Emperor Maximilian" — is Trithemius's reply to the eight questions Maximilian put to him at Boppard: on faith and understanding, on the faith necessary for salvation, on the miracles of unbelievers, on witches and harmful magic, and on related matters. Composed in 1508, it is his central statement on witchcraft and the source from which later demonological writers drew heavily. The questions are set out in an enumerated table and answered in sequence, in the blend of scholastic authority and pastoral caution that marks his shorter treatises.
4 editions: Oppenheym, 1515 · Coloniae, 1534 · Francoforti, 1550 · Moguntiae, 1601
Clavis Polygraphiae
Key to the Polygraphia · 1518
Clavis Polygraphiae — the "Key to the Polygraphia" — is Trithemius's own commentary on his Polygraphiae libri sex, explaining how the six books of cipher tables are constructed and how a correspondent is meant to use them in practice. A cipher manual is of little use without its key, and the Clavis is what made the Polygraphiae operational: it walks through the modi of enciphering and deciphering, the Ave Maria alphabets, and the polyalphabetic tables, tying the abstract apparatus of the six books to the concrete business of sending and recovering a hidden message. It was composed alongside the Polygraphiae in 1508 and printed with it.
Basel, 1518 · provisional reading text · Latin / English
Polygraphiae libri VI (Basel: Furter & Petri, for Haselberg, 1518)
Six Books of Polygraphy (Basel, 1518 first edition) · 1518
Polygraphiae libri VI—“Six Books of Polygraphy”—is the 1518 first edition of Trithemius’s open cryptographic manual, the first printed book on cryptography in the West. He completed the work late in life—the dedication to Emperor Maximilian I is dated 1508—and it was printed posthumously, two years after his death. Where the Steganographia hides its ciphers behind angel-magic, the Polygraphiae teaches the craft in the open: substitution tables, transposition grids, the “Ave Maria” cipher in which plaintext becomes a pious Latin sentence, and numerical codes. Its six books move from simple to complex, culminating in the polyalphabetic tabula recta.
3 editions: Basel, 1518 · Francofurti, 1550 · Argentoratum, 1600
Clavis Generalis Triplex in Libros Steganographicos
Threefold General Key to the Steganographic Books · 1608
Clavis Generalis Triplex in Libros Steganographicos — the "Threefold General Key to the Steganographic Books" — is Trithemius's own explanatory key to his most notorious work, the Steganographia. The Steganographia (composed around 1499–1500) circulated only in manuscript during his lifetime and earned him lasting accusations of necromancy, because its cipher instructions are dressed as conjurations of angels and spirits; it was printed posthumously in 1606 and placed on the Index. The Clavis is the antidote Trithemius supplied: a compact decryption key demonstrating that the "spirit names" resolve into a cryptographic system, not a magical one. It sets out, modus by modus, the explicit substitution alphabets by which each cipher is to be read.
Francofurti, 1608 · provisional reading text · Latin / English
Veterum Sophorum Sigilla et Imagines Magicae (pseudo-Trithemian, 1612)
Seals and Magical Images of the Ancient Sages (pseudo-Trithemian astral-magic text) · 1612first English
Veterum Sophorum Sigilla et Imagines Magicae — "The Seals and Magical Images of the Ancient Sages" — is a short astral-magical text: instructions for engraving planetary seals and images on stones and gems, keyed to the divine name Tetragrammaton and the courses of the planets, "for producing miraculous effects." It belongs to the later esoteric corpus that attached itself to Trithemius's name after his death.
2 editions: Marne / Aubry, 1612 · e-rara, 1612
Steganographia, hoc est: Ars per occultam scripturam
Steganography: The Art of Hidden Writing · 1621
The Steganographia is Trithemius's most famous and most notorious work: a treatise in three books, written about 1499–1500 and circulated for a century in manuscript before it was first printed (Frankfurt, 1606). On its surface it is a manual of angel-magic — long conjurations addressed to spirit-princes and their subordinate spirits, each governing a quarter of the heavens, a wind, or an hour of the day. Beneath that surface it is a cryptographic system: the "conjurations" are cover-text, and the real message is carried by the spirit-names and the numeric keys tabulated for each prince. It was the disguise that undid him. Manuscript copies reached readers they were not meant for — Carolus Bovillus among them — who took the spirit-magic at face value and accused Trithemius of necromancy; the book was placed on the Index, and the third book's reputation as genuinely demonic persisted until its cipher was solved — first by Thomas Ernst (1996), then independently by Jim Reeds (1998). Trithemius's own answer to the charge is the Trithemius sui ipsius vindex of 1616, also in this corpus (prdl-32287).
Darmbstadii. Ex officina typographica Balthasaris Aulæandri, 1621 · provisional reading text · Latin / English