by DAVID KAHN
The Carbonari, an antimonarchical, liberal, secret political society that flourished in Italy, and later in France, early in the 19th century, may have used a cipher based on a keyphrase. This phrase was written beneath the plaintext alphabet, thereby becoming the ciphertext alphabet. Superscribed numerals differentiated repeated letters in the keyphrase. Paul Féval, a prolific author of popular adventure novels, employed such a system in Les Compagnons du Silence, a novel published in 1857 and involving a Carbonari-like secret society. The keyphrase was the fictional society’s motto, meaning “Happy friends, let us go to suffering,” but Féval erroneously used ALLIEGRE for ALLEGRI, throwing most of the phrase out of phase:
In this, carbonari would become IAA4MNA3AA4I3. In 1834 a cryptogram with a similar aspect was seized upon a member of the French Carbonari.
Though the whole aim of science is to bring things to light, scientists have sometimes had to conceal their results for fear of persecution. Porta’s Accademia dei Lincei corresponded in cipher with Johann Eck. When Galileo Galilei discovered with his new telescope that Venus went through phases like the moon, thereby powerfully supporting the Copernican theory, he risked getting into serious trouble with the Catholic Church, which was soon to declare that theory heretical. Consequently he recorded his discovery as an anagram in a letter to Johannes Kepler: HAEC IMMATURA A ME JAM FRUSTRA LEGUNTUR O.Y. (“These unripe things are now read by me in vain”), with the O.Y. two letters that he could not fit in. The plaintext further hid the names of the celestial bodies under mythological allusions, referring to Venus’ character as the goddess of love, and Cynthia’s as the goddess of the moon: Cynthiae figuras aemulatur mater amorum (“The mother of love imitates the phases of Cynthia”). In the same way, Christiaan Huygens established his priority in the discovery that Saturn had rings. Instead of anagramming his plaintext into another sensible text, however, he simply alphabetized it in a letter to a friend: 7 A’S, 5 C’S, 1 D, 5 E’S, 1 G, 1 H, 7 I’S, 4 L’S, 2 M’S, 9 N’S, 4 O’S, 2 P’S, 1 Q, 2 R’S, 1 S, 5 T’S, and 5 U’S. This stood for Annulo cingitur tenui plano, nusquam cohaerente, ad ecliptican inclinato (“It is girdled by a thin flat ring, nowhere touching, inclined to the ecliptic”). In 1711, the great English architect Sir Christopher Wren, stimulated by the promise of a reward offered by Parliament to the inventor of a means of determining the longitude of a ship at sea, transmitted three short cipher messages to the Royal Society describing three instruments for this: (1) OZVCVAYINIXDNCVOCWEDCNMAL-NABECIRTEWNGRAMHHCCAW, (2) ZEIYEINOIEBIVTXESCIOCPSDEDMNANHSEFPRPI-WHDRAEHHXCIF, (3) EZKAVEBIMOXRFCSLCEEDHWMGNNIVEOMREWWERRCSHEP-CIP. Each was to be read backwards, omitting every third letter. There are a few errors. Why Wren enciphered something that he should have been making plain as day remains unknown, but in any event he did not win the reward.
More recently, Alfred C. Kinsey and his associates encoded the replies of interviewees about their sexual habits for Sexual Behavior in the Human Female. Only four persons on the staff of the Institute for Sex Research could read the code, which recorded the answers in the forms of X’s and a few checks, dashes, and incomprehensible abbreviations in columns. Kinsey explained that “Recording the data in code in the presence of the subject has done a good deal to convince him or her of the confidence of the record. Even though anonymity is ordinarily guaranteed by the statement which caps most questionnaires, many persons still fear that there may be some means by which they can be identified if they write out answers to printed questions. They fear, and not without some justification in the history of such studies, that a record made in plain English may be read by other persons who obtain access to the file. It is not to be forgotten that our sex laws and public opinion are so far out of accord with common and everyday patterns of social behavior that many persons might become involved in social or legal difficulties if their sexual histories became publicly known.”
Lovers could sometimes find themselves in the same difficulties if their liaisons became known. Consequently Ovid, in his Art of Love, offered counsel on how to correspond clandestinely, mentioning some primitive forms of secret ink:
Tuta quoque est fallitque oculus e lacte recenti
Littera: carbonis pulvere tange, leges.
Fallet et umiduli quae fiet acumine lini,
Et feret occultas pura tabella notas.
Or: “A letter is also safe and escapes the eye when written in new milk; touch it with coal dust and you will read. That too will deceive which is written with a stalk of moistened flax, and a pure sheet will bear hidden marks.” He also advised using pronouns of the opposite sex, such as HIM for her.
Secret correspondence among lovers ranges from simple notes clandestinely passed in schoolrooms to the far more elaborate systems of the rich, the royal, and the famous. In 1631, John Winthrop the younger, a future governor of Connecticut, then in his twenties, fell in love with his cousin, Martha Fones, an orphan and ward of his father, John, first governor of the Massachusetts Bay Colony. Somehow they managed to get married, when he was 24, and, since the mails were irregular and letters were sealed only with wax, they embowered their rather lyrical correspondence the next year within a monalphabetic symbol substitution, he from London, she from Groton. But she died with her first-born and he later remarried. In the 1890s, Seaman L. Wetherell, who had been convicted in Vermont of having had sexual intercourse with a girl under 14, mailed her from prison a copy of The Black Cat magazine, in which he had marked and dotted certain words and letters, spelling out what the court ponderously called “a communication in epistolatory form, expressive of love, and containing a request to write, and an injunction to remember her promise.” Jonathan Swift, whose pen could be sharper and more satiric than any man’s, melted into almost cloying sweetness in the “little language,” which was not much more than a kind of baby talk, of his Journal to Stella, who was really 12-year-old Esther Johnson. He also used a null cipher, in which only the alternate letters counted, as in AL BSADNUK LBOINLPL DFAONR UFAINFBTOY DPIONUFNAD for a bank bill for fifty pound.
Marie Antoinette maintained a most elaborate cryptographic ménage for amatory correspondence, which with her often had political overtones. Though she lived in the age of the nomenclator, she employed a Porta-like cipher for correspondence in Italian, and another based on the novel Paul et Virginie for her Paris correspondence, mostly with Bertrand de Moleville. She enciphered her love letters to Count Axel Fersen, the tall, grave, handsome young Swede who was apparently her lover from the middle of 1783, after his return from helping America in the Revolutionary War. “I can tell you that I love you and indeed that is all I have time for,” one letter began. It ended, “Farewell, most loved and loving of men. I kiss you with all my heart.” Fersen also handled the voluminous correspondence of the Queen and the King in the two months before their famous attempt to escape the Revolution. He used a polyalphabetic system to encipher and decipher the letters to and from the co-conspirators:
The letters of the keyword were found in the column of capitals and the plaintext letter sought in the lowercase pairs, the cipher letter being the other letter of the pair. Thus with key B, d = U and u = D. Fersen used as keys not words like ROI or LOUIS or ROYALE, which might be easily guessed, but simple words like DEPUIS, VOTRE, BATTRE, SEROIT, and so on, which he changed frequently. In addition, he represented important persons by a single letter in a little code list: B = Empress of Russia, F = King of Spain, N = the King, R = Count Fersen, and so on. The messages held their secret well, including the one of May 26, 1791, enciphered with the keyword VERTU, which stated that “the King approves the route.” It was not cryptography’s fault that the escape a few days later of Louis and Marie, disguised as servants and riding in a berlin, was discovered. At Varennes, a cart full of furniture barred the way across a little bridge, and just 24 hours after Marie had pretended to go to bed at the Tuileries, there were cries of “Stop!” and the King and Queen of France and their family were again prisoners of the Revolution—and, eventually, its
victims.
Among the strange means of secret communication to which lovers in the 1800s resorted was perhaps the most public of all channels—the personal advertisements in newspapers, sometimes called the “agony columns.” Apparently unable to contact one another directly through the mails because of parental or other restrictions, the lovers could easily bring a newspaper into the house and thus receive their messages. For secrecy, these were enciphered, but usually in so elementary a system that anyone who applied himself could read their intimacies. In February of 1853, The Times of London carried a Caesar substitution, in which a = V, addressed to Cenerentola: Until my heart is sick have I tried to frame an explanation for you, but cannot. Silence is safest, if the true cause is not suspected. If it is, all stories will be sifted to the bottom. Do you remember our cousin’s first proposition? Think of it. A few months later, on August 19, the same paper carried a cryptogram in an ordinary reversed alphabet—a = Z, z = A—with numbers representing a few words like the and that. The message began My darling, need I say how delighted I was to receive your letter of dear remembrance on my birthday? I beg you not to think I wrote under any irritation. I fear my letters being read by others…. Wheatstone and Babbage often amused themselves by solving these simple missives. Babbage easily read a Caesar substitution of May 13, 1859, addressed to Robert: Why do you not come or write for me? Such grief and anxiety!—Oh! Love Love! His most difficult was a numerical cryptogram of December 21, 1853, addressed to Flo and beginning 1821 82734 29 30 84541. After, apparently, months of trying it as a polyalphabetic and as a homophonic substitution, he finally discovered that it was a polyphonic substitution, in which each cipher number stood for from one to four plaintext letters. It began (with two enciphering errors): Thou image of my heart!
Sometimes people inserted cryptograms just to see if anyone would make them out. A piece of advice about education, enciphered in a Caesar substitution, dated Kensington, was followed a week later by a cleartext advertisement addressed to Kensington, saying, Your cipher is made out; but such good maxims should be written in plain English, that all might benefit. On February 10, 1852, The Times was used to circulate calumny against itself—in cryptographic form, of course: TIG TJOHW IT TIG JFHIIWOLA OG TIG PSGVW. It stood for The Times is the Jefferies of the press, enciphered in a progressive Vigenère with key ABCD … beginning anew with each word. The reference to George Jeffreys, a 17th-century English judge, meant that The Times was a pusillanimous tool of the government and mercilessly severe to its opponents. When the editor of The Times heard about the cryptogram, he, like his queen, was not amused. The family of the explorer Richard Collinson communicated with him privately during his explorations even though they did not know where he was by inserting coded personal notices in The Times. Use of the enciphered personal advertisement seems to have died out, however, perhaps owing to the censorship restrictions of two world wars, perhaps because of the telephone or relaxed parental restrictions.
Still cryptography serves lovers. Early in the 1930s, Thelma, Lady Furness, was being courted by the Prince of Wales, later to become Edward VIII. They cabled each other in code. “I used to resent the time it took me to decode them,” she gushed later. “When one is in love, one wants to know everything all at once, and as the messages were usually long, it seemed to take forever to find out what they said. But the wait was always worth while because in code one need not leave unsaid all the things dear to a woman’s heart.” Unfortunately, she made the mistake, on the eve of a visit to the United States, of asking a friend to look after the prince for her while she was away, and the friend promised that she would. Her name was Wallis Warfield Simpson.
The privacy sought in such communications is sometimes sought even in missives to oneself—in diaries or private notebooks. Well known are the notebooks of Leonardo da Vinci, which he wrote partly in his left-handed mirror writing, partially concealing many of the ideas that were so advanced for their time, such as armored military vehicles and flying machines. Perhaps the earliest diary to be kept cryptographically was that of the Swedish government official Erik Brahe, who kept one in secret characters—a line a day—from 1592 to 1601. Others followed. In colonial America, William Byrd of Virginia, an ancestor of the late Senator Harry F. Byrd of the same state, kept a diary irregularly for a total of about seven years between 1709 and 1741. He wrote in shorthand, using a system identified late in the 1930s by Edward J. Vogel, a Chicago court stenographer who had worked in Yardley’s MI-8, as William Mason’s “La Plume Volante,” or the flying pen. Mrs. Marion Tin-ling transcribed it, finding some difficulty because Byrd often omitted the vowels in that shorthand. Parts of the diary are still unpublished, presumably because of its exceedingly racy character.
General Henri-Gatien Bertrand, Napoleon’s companion during his years of exile on Saint Helena, kept a diary in such highly abbreviated French that it was virtually a code. The entry for January 20, 1821, reads: “N. so. le mat. en cal: il. déj. bi. se. trv. un peu fat; le so. il est f.g.” The interpreter, Paul Fleuriot de Langle, who called his work “translating from French into French—the singular sport and strange pastime,” rendered this passage as Napoléon sort le matin en calèche. Il déjeune bien, se trouve un peu fatigué; le soir, il est fort gai (“Napoleon goes out in the morning in a carriage. He lunches well, finds himself a little tired; in the evening, he is very gay”).
Most famous of secret diaries—and deservedly so—is, of course, Samuel Pepys’. This English civil servant kept his tart, frank diary, probably the most continuously fascinating ever written, from January 1, 1660, to May 31, 1669, when failing eyesight forced him to discontinue it. It fills more than 3,000 closely written pages, all in a shorthand of Thomas Shelton’s called “tachygraphy.” Eleven of its shorthand letters were little removed from the outlines of the ordinary longhand forms, and it had five places for the vowel-dots, but a vowel in the middle of a word was expressed by placing the following consonant in the position that the vowel-dot would have assumed. Shelton suggested a list of contracted words—books of the Bible, frequent sermon phrases—and gave arbitrary characters to 265 common words. Among these were 2 for to, a larger 2 for two, 3 for grace, 4 for heart, 5 for because, 6 for us, and so on.
Pepys probably learned it at Magdalene College, Cambridge, where it was in favor; he seems to have based his diary upon the edition of 1641, apparently the sixth since Shelton’s first publication in 1620. But though this apparently widespread knowledge would seem to have made it impossible for Pepys to have used shorthand for secrecy, that appears in fact to have been one of his motives for using it. In the first place, he once remarked to a friend about how undesirable it would be to have it generally known that he kept a diary. In the second place, shorthand was uncommon enough in 17th-century England for many people to believe it could be used as a secret cipher. Some Protestants, fearing that the Catholics would entirely suppress the Bible if they had the opportunity, copied it out in shorthand to preserve it. Pepys increased the secrecy by writing the more salacious passages usually in French, sometimes in Latin, Greek, or Spanish, and by interpolating null symbols of his own invention. In addition to the secrecy of shorthand, Pepys undoubtedly liked its convenience, and much of the charm of his diary may derive from the mentally uncensored way in which shorthand’s speed permitted him to write it.
A page of Samuel pepys’ original shorthand diary
The six small octavo volumes of the diary reposed in the Pepysian collection at Magdalene College for three or four generations after Pepys’ death, unread beneath its semisecret script. Shelton’s tachygraphy had joined the multitude of all-but-forgotten outdated shorthand systems; the volumes contained no key; and although the collection included Pepys’ longhand transcript of his shorthand account of the adventures of Charles II, the librarians did not know about it. Upon the publication of the diary of John Evelyn, Pepys’ contemporary, the master of Magdalene thought that Pepys’ diary might also shed light on that exciting perio
d in English history, since Pepys had held some high posts in the Admiralty. He showed the diary apparently to Thomas Grenville, a statesman and book collector. According to oral tradition at the college, Grenville took the diary up to bed with him one evening and reappeared at breakfast the following morning with several pages deciphered. He gave this key to John Smith, an undergraduate in St. John’s College and a shorthand reporter, who took from 1819 to 1822, working usually 12 or 14 hours a day, to transcribe the diary. He did it with skill and accuracy—in general, only half a dozen minor errors will be found in 20 pages.
When he finished, he had disclosed, not just some titillating personal recollections, but a document unparalleled for the way it reveals a man. The diary was published in 1825 and has probably never been out of print since. Smith afterwards spent an uneventful life, dying in 1870 after 38 untroubled years as rector at Baldock, Hertfordshire. The diary has become a classic of literature, and literature must owe this ornamant in part to the cryptographic secrecy of the shorthand, in which Pepys felt safe in setting down his most intimate, his most human thoughts.
Cryptology has enriched literature in other ways. Many of the authors of antiquity—among them Homer and Herodotus—mention secret writing. But they allude to events believed to be historical. Not until the Renaissance, when cryptology became more widely used and hence known to many literate men, could it serve as a topic in literature. The author who first employed it did not merely brush the subject, he seized it with both hands, danced it around, and exuberantly roared out a stream of mirth poking fun at the whole business. He was, naturally, Francois Rabelais:
When Pantagruel had read the superscription [in a missive from a lady, saying “To the most loved by the fair and the least loyal of the brave”], he was much amazed, and therefore demanded of the said messenger the name of her that had sent it: then opened he the letter, and found nothing written in it, nor otherwayes inclosed, but only a gold ring, with a square table-diamond. Wondering at this, he called Panurge to him, and shewed him the case; whereupon Panurge told him, that the leafe of paper was written upon, but with such cunning and artifice, that no man could see the writing at the first sight, therefore to finde it out he set it by the fire, to see if it was made with Sal Ammoniack soaked in water; then put he it into the water, to see if the letter was written with the juice of Tithymalle: after that he held it up against the candle, to see if it was written with the juice of white onions.
