« AnteriorContinuar »
apud milites concionabundus, sic orsus est; Vos (inquit) his innocentibus et miserrimis lucem et spiritum reddidistis; sed quis fratri meo vitam, quis fratrem mihi reddit? quem missum ad vos a Germanico exercitu de communibus commodis nocte proxima jugulavit per gladiatores suos, quos in exitium militum habet atque armat. Responde, Blæse, ubi cadaver abjeceris? Ne hostes quidem sepulturam invident. Cum osculis, cum lachrymis dolorem meum implevero, me quoque trucidari jube; dum interfectos, nullum ob scelus, sed quia utilitati legionum consulebamus, hi sepeliant.1 Quibus verbis invidiæ ac consternationis nimium quantum concivit; adeo ut nisi brevi postea innotuisset nihil horum fuisse, quinetiam fratrem eum nunquam habuisse, vix a præfecto milites manus abstinuissent; ille vero rem totam tanquam fabulam in scena peregit.
Nunc vero ad colophonem pervenimus tractatus nostri de Doctrinis Rationalibus. In quibus, licet a partitionibus receptis interdum recesserimus, nemo tamen existimet nos illas omnes improbare partitiones quibus usi non sumus. Duplex enim nobis imponitur necessitas partitiones mutandi. Una, quia hæc duo, nimirum res natura proximas in unam classem redigere, et res ad usum promendas conjicere in unum cumulum, fine ipso et intentione sunt omnino diversa. Exempli gratia; secretarius aliquis regis aut reipublicæ, in musæo chartas suas ita proculdubio distribuit, ut quæ similis sint naturæ simul componat; veluti fœdera seorsum, seorsum mandata, literas ab exteris, literas domesticas, et similia, seorsum omnia: contra, in scrinio aliquo particulari illas simul componit, quas, licet diversi generis sunt, simul tamen usui fore existimet. Sic
nimirum, in hoc universali scientiæ repositorio, nobis pro natura rerum ipsarum partitiones erant instituendæ ; cum tamen, si particularis aliqua scientia fuisset pertractanda, partitiones fuissemus secuti usui et praxi potius accommodatas. Altera necessitas partitiones mutandi est, quia Desideratorum ad scientias adjectio, et eorum cum reliquis in integrum corpus redactio, etiam, per consequentiam, scientiarum ipsarum partitiones transtulit. Nam (demonstrationis gratia), esto quod artes quæ habentur rationem habeant numeri 15, adjectis autem Desideratis numeri 20. Dico quod partes numeri 15, non sunt eædem partes quæ numeri 20. Nam partes numeri 15, sunt 3 et 5;
partes vero numeri 20 sunt 2, 4, 5, et 10.
[The following Notes on some old treatises on the art of writing in cipher are referred to by Mr. Ellis, at p. 420. note 1.-J. S.]
THE earliest writer, I believe, on ciphers, except Trithemius whom he quotes, is John Baptist Porta, whose work De occultis literarum notis was reprinted in Strasburg in 1606. The first edition was published when Porta was a young man. The species of ciphers which Bacon mentions are described in this work. What he calls the ciphra simplex is doubtless that in which each letter is replaced by another in accordance with a secret alphabet. (Porta, ii. c. 5.) The manner of modifying this by introducing nonsignificants and by other contrivances is described in the following chapter. The wheel cipher is described in chapters 7, 8, 9. It is that in which the ordinary alphabet and a secret one are written respectively on the rim of two concentric disks, so that each letter of the first corresponds in each position of the second (which is movable) to a letter of the secret alphabet. Thus in each position of the movable disk we have a distinct cipher, and in using the instrument this disk is made to turn through a given angle after each letter has been written. The ciphra clavis is described by Porta, book ii. 15, 16. It is a cipher of position; that is, one in which the difficulty is obtained not by replacing the ordinary alphabet by a new one, but by deranging the order in which the letters of a sentence or paragraph succeed each other.
This is done according to a certain form of words or series of numbers which constitute the key. The cipher of words was given by Trithemius and in another form by Porta, ii. 19. (and in a different shape, v. 16.). It is a cipher which is meant to escape suspicion. Each letter of the alphabet corresponds to a variety of words arranged in columns. Any word of the first column followed by any of the second, and that followed by any of the third, &c., will make, with the help of a non-significant word occasionally introduced, a perfectly complete sense; and by the time the last alphabet has been used, a letter on some indifferent subject has been written. Only sixty alphabets are given by Porta, and therefore the secret communication can consist only of sixty letters. It is worth remarking that when Porta wrote it was usual to put the sign of the cross at the head of an ordinary epistle. The first of his alphabets corresponds not to a series of words but to two and twenty different modifications of the figure of a cross, and his second alphabet similarly corresponds to two and twenty different modifications of the introductory flourish. His sixtieth alphabet is of the same kind. We see here perhaps whence Bacon derived his idea of giving significance to seemingly accidental modifications of the characters of ordinary writing.
The idea of a biliteral alphabet, which Bacon seems to claim as his own, is employed, though in a different manner, by Porta. His method is in effect this. He reduces the alphabet to sixteen letters, and then takes the eight different arrangements aaa, aba, &c., to represent them; each arrangement representing two letters indifferently: the ambiguity arising from hence he seems to disregard. In this manner he reduces any given word or sentence to a succession of a's and b's. At this point his method, of which he has given several modifications, departs wholly from Bacon's. Let us suppose the biliteral series to commence with aababb. A word of two syllables and beginning with A indicates that two a's commence the series; any monosyllable will serve to
show that one b follows, another that it is succeeded by one a, and then any dissyllable will stand for bb. Thus Amo te mi fili or Amat qui non sapit will represent the biliteral arrangement aababb, and so on on a larger scale. Porta's method is therefore not, like Bacon's, a method scribendi omnia per omnia, but only omnia per multa. Still the analogy of the two methods is to be remarked: both aim at concealing that there is any but the obvious meaning, and both depend essentially on representing all letters by combinations of two only. See the De oc. Lit. Signis. v. c. 3.
The Polygraphia of Trithemius (dedicated to Maximilian in 15081) consists of six books. The first four contain extensive tables constituting four different ciphræ verborum ; the first and second of which are significant, and relate, the former to the second person of the Trinity, and the latter to the Blessed Virgin. The fifth and sixth books are of less importance. Trithemius, written in the cipher of the second book, becomes "Charitatem pudicissimæ Virginis Mariæ productricis coexistentis verbi, robustissimi commilitonis mei dilectissimi devotissime benedicamus; vivificatrix omnium," &c.
Traicté des Chiffres, ou secrètes manières d'escrire, par Blaise de Vigenère, Bourbonnois. (Paris, 1587.)
This work is described by the author as what he had saved of his work “ Du Secrétaire,” written in Italy in 1567 and 68. The two first books were stolen at Turin in 1569. The third is the foundation of the present work. (v. f. 285. verso.) He says he had revealed nothing of its contents.
The two authors whom he chiefly mentions are Trithemius and Porta; that is, modern authors; for there is a great deal said of the Cabala. The key ciphers of which Porta speaks he ascribes to a certain Belasio, who employed it as early as
1 The edition of 1600 is that I use.