The Craft of Intelligence (9 page)

I am, of course, not speaking here of ordinary mail, although postal censorship has itself often played a significant role in intelligence work. However, except in the detection of secret writing, there is little technology involved in postal censorship. Modern communications intelligence, on the other hand, is a highly technical field, one that has engaged the best mathematical minds in an unceasing war of wits that can easily be likened to the battle for scientific information which I described a little earlier.

Every government takes infinite pains to invent unbreakable systems of communication and to protect these systems and the personnel needed to run them. At the same time, it will do everything in its power to gain access or insight into the communications of other governments whose policies or actions may be of real concern to it. The reasons for this state of affairs on both sides is obvious. The contents of official government messages, political or military, on “sensitive” subjects constitute, especially in times of crisis, the best and “hottest” intelligence that one government can hope to gather about another.

There is a vast difference between the amateur and professional terminology in this field. If I stick to the amateur terms, I shall probably offend the professionals, and if I use the professional terms, I shall probably bore and confuse the amateur. My choice is an unhappy one and I will be brief. In a code, some word, symbol or group of symbols is substituted for a whole word or even for a group of words or a complete thought. Thus, “XLMDP” or “79648,” depending upon whether a letter or number code is used, could stand for “war” and every time they turn up in a message that is what they mean. When the Japanese Government set up the famous “East Winds” code for their diplomats in the United States in December, 1941, they were prepared to indicate through the simplest prearranged code words that an attack in the Pacific was forthcoming.

In a cipher, a symbol, such as a letter or number, stands for a single letter in a word. Thus, “b” or “2” can mean “e” or some other letter. In simple ciphers the same symbol always stands for the same letter. In the complex ciphers used today, the same symbol can stand for a different letter each time it turns up. Sometimes a message is first put into code, and then the code is put into cipher.

The United States military forces were able to resort to rather unusual “ready-made” codes during World War I, and in a few instances during World War II, in communications between units in the field. These resources were our native American Indian languages, chiefly the Navajo language, which has no written forms and had never been closely studied by foreign scholars. Two members of the same tribe at either end of a field telephone could transmit messages which no listener except another Navajo could possibly understand. Needless to say, neither the Germans nor the Japanese had any Navajos.

In modern terminology, the word “crypt,” meaning “something hidden,” conveniently gets around the distinction between codes and ciphers since it refers to all methods of transforming “plain text” or “clear text” into symbols. The overall term for the whole field today is “cryptology.” Under this broad heading we have two distinct areas. Cryptography has to do with making, devising, inventing or protecting codes and ciphers for the use of one’s own government. Cryptanalysis, on the other hand, has to do with breaking codes and ciphers or “decrypting” them, with translating someone else’s intercepted messages into proper language. To put one’s own messages into a code or cipher is to “encrypt” them. However, when we translate our own messages back into plain language, we are “deciphering.”

A cryptogram or cryptograph would be any message in code or cipher. “Communications intelligence” is information which has been gained through successful cryptanalysis of other people’s traffic. And now, having confused the reader completely, we can get to the gist of the matter.

The diplomatic service, the armed services and the intelligence service of every country use secret codes and ciphers for classified and urgent long-distance communications. Transmission may be via commercial cable or radio or over special circuits set up by governments. Anyone can listen in to radio traffic. Also, governments, at least in times of crisis, can usually get copies of the encrypted messages that foreign diplomats stationed on their territory send home via commercial cable facilities. The problem is to break the codes and ciphers, to “decrypt” them.

Certain codes and ciphers can be broken by mathematical analysis of intercepted traffic, i.e., cryptanalysis, or more dramatically and simply by obtaining copies of codes or code books or information on cipher machines being used by an opponent, or by a combination of these methods.

In the earlier days of our diplomatic service, up to World War I, the matter of codes was sometimes treated more or less cavalierly, often with unfortunate results. I remember a story told me as a warning lesson when I was a young foreign service officer. In the quiet days of 1913, we had as our Minister in Rumania an estimable politician who had served his party well in the Midwest. His reward was to be sent as Minister to Bucharest. He was new to the game and codes and ciphers meant little to him. At that time our basic system was based on a book code, which I will call the Pink Code, although that was not the color we then chose for its name. I spent thousands of worried hours over this book, which I have not seen for over forty years, but to this day I can still remember that we had six or seven words for “period.” One was “PIVIR” and another was “NINUD.” The other four or five I do not recall. The theory than was—and it was a naïve one—that if we had six or seven words it would confuse the enemy as to where we began and ended our sentences.

In any event, our Minister to Rumania started off from Washington with the Pink Code in a great, sealed envelope and it safely reached Bucharest. It was supposed to be lodged in the legation’s one safe. However, handling safe combinations was not the new Minister’s forte, and he soon found it more convenient to put the code under his mattress, where it rested happily for some months. One day it disappeared—the whole code book and the Minister’s only code book. It is believed that it found its way to Petrograd.

The new Minister was in a great quandary, which, as a politician, he solved with considerable ingenuity. The coded cable traffic to Bucharest in those days was relatively light and mostly concerned the question of immigrants to the United States from Rumania and Bessarabia. So when the new Minister had collected a half-dozen coded messages, he would get on the train to Vienna, where he would quickly visit our Ambassador. In the course of conversation, the visitor from Bucharest would casually remark that just as he was leaving he had received some messages which he had not had time to decode and could he borrow the Ambassador’s Pink Code. (In those good old days, we sent the same code books to almost all of our diplomatic missions.) The Minister to Bucharest would then decipher his messages, prepare and code appropriate replies, take the train back to Bucharest and, at staged intervals, send off the coded replies. For a time everything went smoothly. The secret of the loss of the code book was protected until August, 1914, brought a flood of messages from Washington as the dramatic events leading up to World War I unrolled. The Minister’s predicament was tragic—trips to Vienna no longer sufficed. He admitted his dereliction and returned to American politics.

The uncontrollable accidents and disasters of war sometimes expose to one opponent cryptographic materials used by the other. A headquarters or an outpost may be overrun and in the heat of retreat code books left behind. Many notable instances of this kind in World War I gave the British a lifesaving insight into the military and diplomatic intentions of the Germans. Early in the war the Russians sank the German cruiser
Magdeburg
and rescued from the arms of a drowned sailor the German naval code book, which was promptly turned over to their British allies. British salvage operations on sunken German submarines turned up similar findings. In 1917 two German dirigibles, returning from a raid over England, ran into a storm and were downed over France. Among the materials retrieved from them were coded maps and code books used by German U-boats in the Atlantic.

An American naval exploit which took place toward the end of World War II has given us an even more thrilling story of the capture of enemy code and cipher material. This was the result of a carefully laid plan and not of a lucky accident. A German submarine, the U-505, was captured, intact, on June 4, 1944, off the coast of French West Africa by units of the United States Navy under the command of Rear Admiral Daniel V. Gallery.

During World War II, Allied action resulted in the destruction of over seven hundred German U-boats. The U-505, which now reposes in the Museum of Science and Industry, Chicago, was the only one that was brought back afloat and in one piece. It had been the consistent practice of the German U-boat crews whose subs were forced to surface and surrender to insure that the submarine would sink as the crew abandoned ship. In this instance, however, as the result of skillful preparation, a boarding party from Admiral Gallery’s task force managed to get abroad the U-505 just as its own crew was abandoning it after having set its valves for scuttling. At the risk of their lives and not knowing how many seconds they had before the submarine would take its final plunge, some ten men from the American naval boarding crew charged down the hatch and closed the scuttling valves just in the nick of time. Their escape was later aided by a German sailor. He had jumped overboard and was swimming near the sinking German sub when a member of the boarding crew hauled him aboard again and got him to disclose the workings of a conning tower hatch which was on the escape route of the Americans who had gone below. As they threw him back into the water, it was with a heartfelt “Thanks, bud,” but rescue was at hand for him and the other German crew members.

All the records and files and technical equipment aboard the sub, including its codes and ciphers, were rescued, and the submarine was safely towed to Bermuda.

But this was not the end of the story. If the Nazis had learned that the submarine had not been scuttled or destroyed before capture, they would have been alerted to the probable seizure of the code and cipher material aboard and would never again have used them. Obviously several thousand American naval personnel, from the beginning to the end of the operation of capture and of towing, knew the facts, and for many this was their great story of the war. The problem of impressing upon all these sailors the importance of keeping the capture secret was a bigger task even than capturing the submarine itself. But this was done with success. The Germans believed that the submarine had gone to its watery grave, carrying with it the secrets which in fact proved very useful to us.
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Military operations based on breaking of codes will often tip off the enemy, however. When, during World War I, the Germans noticed that their submarines were being cornered with startling frequency, it was not hard for them to guess that communications with their underwater fleet were being read. As a result, all codes were immediately changed. There is always the problem, then, of how to act on information derived in this manner. One can risk terminating the usefulness of the source in order to obtain an immediate military or diplomatic gain, or one can hold back and continue to accumulate an ever-broadening knowledge of the enemy’s movements and actions in order eventually to inflict the greatest possible damage.

Actually, in either case, the attempt is usually made to protect the real source and keep it viable, by giving the enemy fake indications that some other kind of source was responsible for the information acquired. Sometimes an operation that could damage the adversary is not undertaken if it would alert the enemy to the fact that its origin was solely due to information obtained by reading his messages.

During World War I, the first serious American cryptanalytic undertaking was launched under the aegis of the War Department. Officially known as Section 8 of Military Intelligence, it liked to call itself the “Black Chamber,” the name used for centuries by the secret organs of postal censorship of the major European nations. Working from scratch, a group of brilliant amateurs under the direction of Herbert Yardley, a former telegraph operator, had by 1918 become a first-rate professional outfit. One of its outstanding achievements after World War I was the breaking of the Japanese diplomatic codes. During negotiations at the Washington Disarmament Conference in 1921, the United States wanted very much to get Japanese agreement to a 10:6 naval ratio. The Japanese came to the conference with the stated intention of holding to a 10:7 ratio. In diplomacy, as in any kind of bargaining, you are at a tremendous advantage if you know your opponent is prepared to retreat to secondary positions if necessary. Decipherment of the Japanese diplomatic traffic between Washington and Tokyo by the Black Chamber revealed to our government that the Japanese were actually ready to back down to the desired ratio if we forced the issue. So we were able to force it without risking a breakup of the conference over the issue.

The “Black Chamber” remained intact, serving chiefly the State Department, until 1929, when Secretary Stimson refused to let the department avail itself further of its services. McGeorge Bundy, Stimson’s biographer, provides this explanation:

Stimson adopted as his guide in foreign policy a principle he always tried to follow in personal relations—the principle that the way to make men trustworthy is to trust them. In this spirit he made one decision for which he was later severely criticized: he closed down the so-called Black Chamber. . . . This act he never regretted . . . . Stimson, as Secretary of State, was dealing as a gentleman with the gentlemen sent as ambassadors and ministers from friendly nations.
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