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Tag: Steganographia

Eco: Polygraphies

Chart_in_the_hand_of_Dr_John_Dee._Steganographiae

John Dee (1527-1609), an excerpt from Steganographiae, aka Peniarth MS 423D, astrological texts in Latin, 1591. Steganographiae was originally composed by Johannes Trithemius in the 1490’s. Infamous as a work of cryptography, this excerpt was copied by hand by Dr. Dee. Peniarth MS 423D is held by the National Library of Wales. This file is made available under the Creative Commons CC0 1.0 Universal Public Domain Dedication. All rights are waived worldwide under copyright laws. This file can be copied, modified, and distributed with no permissions required.  

“Steganographies were used to cipher messages in order to guarantee secrecy and security.  However, even though disregarding many terminological details (or differences) used today by the cryptographers, one must distinguish between the activity of coding and decoding messages when one knows the key, or code, and cryptoanalysis (sic); that is, the art of discovering an unknown key in order to decipher an otherwise incomprehensible message.

Both activities were strictly linked from the very beginning of cryptography: if a good steganography could decode a ciphered message, it ought to allow its user to understand an unknown language as well.

When Trithemius wrote his Polygraphiae, which was published in 1518, before his Steganographia, and did not earn the sinister fame of the latter work, he was well aware that, by his system, a person ignorant of Latin might, in a short time, learn to write in that “secret” language (1518: biiii) (sic).

Speaking of TrithemiusPolygraphia, Mersenne said (Quaestiones celeberrimae in Genesim, 1623: 471) that its “third book contains an art by which even an uneducated man who knows nothing more than his mother tongue can learn to read and write Latin in two hours.”

Steganography thus appeared both as an instrument to encipher messages conceived in a known language and as the key to deciphering unknown languages.

In order to cipher a message one must substitute the letters of a plain message (written in a language known by both the sender and the addressee) with other letters prescribed by a key or code (equally known by sender and addressee).

To decipher a message encoded according to an unknown key, it is frequently sufficient to detect which letter of the encoded message recurs most frequently, and it is easy to infer that this represents the letter occurs most frequently in a given known language.

Usually the decoder tries various hypotheses, checking upon different languages, and at a certain point finds the right solution.

The decipherment is made, however, more difficult if the encoder uses a new key for every new word of the message. A typical procedure of this kind was the following. Both the encoder and the decoder refer to a table like this:

Umberto Eco, Table, The Search for the Perfect Language, Polygraphies, Trithemius, p. 195

Umberto Eco, The Search for the Perfect Language, p. 195.

Now, let us suppose that the key is the Latin word CEDO. The first word of the message is encoded according to the third line of the table (beginning with C), so that A becomes C, B becomes D and so on.

The second words is encoded according to the fifth line (beginning with E), so that A becomes E and so on. The third word is encoded according to the fourth line, the fourth according to the fifteenth one . . . At the fifth word one starts the process all over again.

Naturally the decoder (who knows the key) proceeds in the opposite way.

In order to decipher without knowing the key, if the table is that simple and obvious, there is no problem. But even in cases of more complicated tables the decipherer can try with all possible tables (for instance, with alphabets in reverse order, with alternate letters, such as ACEG), and it is usually only a matter of time before even the most complex of codes are broken.

Observing this, Heinrich Hiller, in his Mysterium artiis steganographicae novissimum (1682), proposed to teach a method of learning to decipher messages not only in code, but also in Latin, German, Italian and French, simply by observing the incidence of each letter and diphthong in each language.

In 1685, John Falconer wrote a Cryptomenysis patefacta: or the Art of Secret Information Disclosed Without a Key, where he noted that, once someone has understood the rules of decipherment in a given language, it is possible to do the same with all the others (A7v).”

Umberto Eco, The Search for the Perfect Language, translated by James Fentress, Blackwell. Oxford, 1995, pp. 194-6.

Eco: Kabbalism & Lullism in the Steganographies

060224

Johannes Trithemius (1462-1516), Polygraphiae libri sex, Basel, 1518. Courtesy of the Shakespeare Folger Library as file number 060224. Joseph H. Peterson at the Esoteric Archives digitized a copy of the complimentary work on steganography held by the British Library in 1997. That work is listed as Trithemius, Steganographic: Ars per occultam Scripturam animi sui voluntatem absentibus aperiendi certu, 4to, Darmst. 1621. London, British Library. This work is in the public domain in its country of origin and other countries and areas where the copyright term is the author’s life plus 100 years or less.   

“A peculiar mixture of kabbalism and neo-Lullism arose in the search for secret writings–steganographies. The progenitor of this search, which was to engender innumerable contributions between humanism and the baroque, was the prolific Abbot Johannes Trithemius (1462-1516).

Trithemius made no references to Lull in his works, relying instead on kabbalistic tradition, advising his followers, for instance, that before attempting to decipher a passage in secret writing they should invoke the names of angels such as Pamersiel, Padiel, Camuel and Aseltel.

On a first reading, these seem no more than mnemonic aids that can help either in deciphering or in ciphering messages in which, for example, only the initial letters of words, or only the initial letters of even-numbered words (and so on according to different sets of rules), are to be considered.

Thus Trithemius elaborated texts such as “Camuel Busarchia, menaton enatiel, meran sayr abasremon.” Trithemius, however, played his game of kabbala and steganography with a great deal of ambiguity. His Poligraphia seems simply a manual for encipherment, but with his posthumous Steganographia (1606 edition) the matter had become more complex.

Many have observed (cf. Walker 1958: 86-90, or Clulee 1988: 137) that if, in the first two books of this last work, we can interpret Trithemius‘ kabbalist references in purely metaphorical terms, in the third book there are clear descriptions of magic rituals.

Angels, evoked through images modeled in wax, are subjected to requests and invocations, or the adept must write his own name on his forehead with ink mixed with the juice of a rose, etc.

In reality, true steganography would develop as a technique of composing messages in cipher for political or military ends. It is hardly by chance that this was a technique that emerged during the period of conflict between emerging national states and flourished under the absolutist monarchies.

Still, even in this period, a dash of kabbalism gave the technique an increased spice.

It is possible that Trithemius‘ use of concentric circles rotating freely within each other owed nothing to Lull: Trithemius employed this device not, as in Lull, to make discoveries, but simply to generate or (decipher) cryptograms.

Every circle contains the letters of the alphabet; if one rotates the inner wheel so as to make the inner A correspond, let us say, to the outer C, the inner B will be enciphered as D, the inner C as E and so on (see also our ch. 9).

It seems probable that Trithemius was conversant enough with the kabbala to know certain techniques of temurah, by which words or phrases might be rewritten, substituting for the original letters the letters of the alphabet in reverse (Z for A, Y for B, X for C, etc.).

This technique was called the “atbash sequence;” it permitted, for example, the tetragrammaton YHWH to be rewritten as MSPS. Pico cited this example in one of his Conclusiones (cf. Wirzubski 1989: 43).

But although Trithemius did not cite him, Lull was cited by successive steganographers. The Traité des chiffres by Vigenère (1587) not only made specific references to Lullian themes, but also connected them as well to the factorial calculations first mentioned in the Sefer Yezirah.

However, Vigenère simply follows in the footsteps of Trithemius, and, afterwards, of Giambattista Della Porta (with his 1563 edition of De furtivis literarum notis, amplified in subsequent editions): he constructed tables containing 400 pairs generated by 20 letters; these he combined in triples to produce what he was pleased to call a “mer d’infini chiffrements à guise d’un autre Archipel tout parsemé d’isles . . . un embrouillement plus malaisé à s’en depestrer de tous les labrinthes de Crete ou d’Egypte” (pp. 193-4), a sea of infinite cryptograms like a new Archipelago all scattered with isles, an imbroglio harder to escape from than all the labyrinths of Crete and Egypt.

The fact that these tables were accompanied by lists of mysterious alphabets, some invented, some drawn from Middle Eastern scripts, and all presented with an air of secrecy, helped keep alive the occult legend of Lull the kabbalist.

There is another reason why steganography was propelling a Lullism that went far beyond Lull himself. The steganographers had little interest in the content (or the truths) expressed by their combinations.

Steganography was not a technique designed to discover truth: it was a device by which elements of a given expression-substance (letters, numbers or symbols of any type) might be correlated randomly (in increasingly differing ways so as to render their decipherment more arduous) with the elements of another expression-substance.

It was, in short, merely a technique in which one symbol replaced another. This encouraged formalism: steganographers sought ever more complex combinatory stratagems, but all that mattered was engendering new expressions through an increasingly mind-boggling number of purely syntactic operations. The letters were dealt with as unbound variables.

By 1624, in his Cryptometrices et cryptographie libri IX, Gustavus Selenus was designing a wheel of 25 concentric volvelles, each of them presenting 24 pairs of letters. After this, he displays a series of tables that record around 30,000 triples. From here, the combinatory possibilities become astronomical.”

Umberto Eco, The Search for the Perfect Language, translated by James Fentress, Blackwell. Oxford, 1995, pp. 126-8.

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