DECLASSIFIED Authority NND 947003 Strategemata I I TRADECRAFf IN ANCIENT GREECE Rose Mary Sheldon 1 The ancient Greeks knew a great deal about the ins and outs of spying, but they did not make our modern terminology distinctions among intelligence collection, security, counterintelligence, and covert operations. If the Greeks did h~ve a word for it, it was strategemata, the single heading under which they gtouped all such activities. We are able to study these "strategems of war" today, t~anks to the survival of several Greek military handbooks, called strategika biblia. Their chapters on intelligence gathering instruct a commander in what w~uld today be called tradecraft: the finer arts of running agents, sending secret rriessages, using codes. ciphers, disguises, and surveillance. We can also glean information from the works of Greek historians and other ancient writers who, even if they are not primarily concerned with military matters, do refer occa­ sibnally to techniques of secret operations. Here is a look at what these sources h~ve to say about the " how to do it" of ancient spying. Of all the surviving military treatises, by far the best is the one written about ~7 B.C. by Aeneas the Tactician-another name, it is thought, for Aeneas of Stymphalos, general of the Arcadian Confederacy. As a fourth-century com­ mlmder, he very likely served most of his time as a mercenary soldier. The Arcadians had been the first Greeks to turn to soldiering as a profession and were mhre in demand than any other mercenaries. They were said to have been the first practical instructors in the art of war. A man of sagacity, whose use of sources proves he was both well traveled and well read, Aeneas had a keen understanding oflhuman nature. His insight and experience, gathered from a career of adven­ ture, give his work an immediacy lacking in the works compiled in libraries by mere epitomizers. Living in an age when the general alone was the driving power behind the whole army, Aeneas recognized intelligence collection and counter­ intelligence as integral parts of the defense of the state. A commander. could afford to leave nothing to' the initiative and good faith of his subordinates; he could not even trust his own men and often set them as spies against one another. I One of Aeneas' basic observations is that intelligence being sent into or out II of .a fortified city has to be transmitted clandestinely to avoid capture by the enemy; he provides us with the first instructional texts on communications security, and describes in detail IS different methods of sending messages, some of lthem cit>hers. Aeneas probably used recognized and traditional devices, th~ugh he no doubt made additions or refinements of his own. One example involved the use of message boards, wooden tablets covered in wax with messages thJnI inscribed in the wax, a common. vehicle of writing in his day. Aeneas suggested writing the secret message on the wood and then covering the wood wi~h wax in which another, more innocuous message could be written. The device originally comes from Herodotus and was used to transmit one of the most imbortant messages in all of Greek history. Demaratus. a Greek living as an exile . 39 DECLAS Tradecralt I 1 in Persia, learned that King Xerxes of Persia planned to invade Greece. Realizing the danger, Demaratus attempted to warn the Spartans. He scraped the wax off a pair of hinged wooden tablets, wrote his secret message on the wood, and then ctivered the boards again with wax. When the tablets arrived, the daughter of the Spartan King Cleomenes discovered the hidden message, and this discovery makes1 her the first known female cryptanalyst. It was both tragic and ironic that in1 the war that resulted, her own husband, Leonidas, died leading the valiant Spartan band that held the pass at Thermopylae for three days before the P~rsians found a way through. 'I A related method of sending secret messages was to write on a boxwood tablet with good quality black ink, letting it dry and then whitening the tablet (~resumably with white slip) to make the letters invisible. The recipient then immersed the tablet in water to wash away the whitening agent and make the ~riting visible. The same method was used for disguising a message as a votive offering at a local shrine. Aeneas suggests using a wooden plaque with the oicture of a heroic horseman carrying a torch and wearing a white cloak, since sculp­ tlired tablets of this kind were commonly offered at altars. (Vows requiring such offerings were made to heroes on many occasions like childbirth, rescue from shipwreck, or recovery from illness}. The tablet was sent along with an unwitting atcomplice and vosted at whatever temple he went to for prayer. (A dead drop, one might say.) It was later retrieved and soaked in oil to bring out the message . I Bladders, Strokes, and Dots ! One rather amusing way to send a secret message required a bladder large enough to hold a message. (No particular animal is recommended for obvious reasons; the longer the message, the larger the bladder required.) The sender i~flated the bladder, knotted it, and let it dry. A message could then be written o~ the outside of the bladder with a mixture of ink and glue. When the writing dried, the bladder was deflated and stuffed into a flask of appropriate size. The fl:ask was filled with oil and corked. In this state, the secret message was hidden in the flask, and it could be carried around unnoticed. The recipient emptied the flask and removed the bladder to read the message. The bladder was r~usable : an answer could be sent by svonging off the bladder, writing a new ~essage, sealing it back into the flask in the same way, and returning it to the original sender. "Especially secret messages," Aeneas writes, "might take the following forms. Insert a book (probably a scroll) into your traveling gear which has the message coded by marking certain letters with dots at long intervals or by strokes ~f unusual length." Thus OmisPetomenoseLipenoikiAn disguises the word O,la. The recipient merely has to transcribe the marked letters. This method has along history that reaches up until the present. The Washington Post of 24 Avril I ~918, for example, revorted the story of Ram Chandra, an Indian revolutionary, who received information for his own newsoaver in San Francisco through specially marked copies of the Koran sent from India which the Indian censors ~ould not touch. A variant method requires using two copies of the same book I ~nd sending a code seoarately to indicate the designated words or letters; but this refinement had to await the invention of printing. The printing press both ~tandardized books and made them easily available to the general public; and I 4o I I DECLASSIFIED Authority NND 947003 I - Tradecraft I the success of this method requires that the unaltered originals be identical in every detail. · : David Kahn in his study The Codebreakers explains some of Aeneas' methods for encoding messages. Among the simplest was replacing vowels for the plain text by dots: one for aloha, two for epsilon, etc. A typical message would look like this: "Dionysius Docked" D:.::N:::S:.:.:S D::CK:D "LET HERACLEIDES COME" L:T H:R.CL::.D:S C::M: Aeneas Tacticw, 31.31 Loeb edition. p. 171 j A more complicated steganographic system used a disk that bore holes representing the letters of the alphabet. The encipherer passed yarn through the hbles that represented the letters of his messages and the decipherer would undo the yarn and get the text in reverse. The holes in the center were used in between tne letters that had to be repeated. Hermann Diels gives us a reconstruction: ~ similar method used an astraga) (a . I sheep's ankle bone) instead of a disk. The astraga) had four flat sides which could be marked with dots; they were frequently used as dice. The 24letters of the alphabet naturally fall into four :;;.... gtoups of six. The thread would be ~ p~ssed through the appropriate letters with a needle. When this operation was finished, the appearance would be of a simple astragal with a ball of thread afound it. The recipient would have to ubwind it and transcribe the message. This device is the one certain invention Hermann Diels attributed solely to Aeneas and not t\nlike Technd:. p . 74 traceable to another source. Leipzig, 1924 I I Simple, uncoded messages could be disguised in several ways. They were w!itten on thin strips of papyrus, then concealed in the shoulder of a tunic, tied to the bridle of a horse, or sewn into the leather skirts on a soldier's cuirass. Aeneas even reoorts a man from Ephesus who sent a message written on leaves bound t~ a wound on his leg. I In special cases a message might need protection from water or mud. Such m'essages, written on sheets of beaten tin, were sewn into sandals and walked through a checkooint. If the communicators worked carefully, they could even slip the message unnoticed into the sandals of an unsuspecting person and then retrieve it while he slept. Similarly, small, rolled and inscribed plates of lead I could hang from a woman's ears as earrings. One Roman example from a later u¢e shows the general Hirtius sending messages on lead plates tied to the arms of a soldier who then swam the Scultenna River.