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SIGINT
The Secret History of Signals Intelligence 1914â"45
By Peter Matthews The History Press
Copyright © 2013 Peter Matthews
All rights reserved.
ISBN: 978-0-7524-9301-5
CHAPTER 1
From Cables to Codes
Cable Wars
Telephone and telegraph communication networks had already changed the world of commerce and diplomacy in the ten years before the war. Now the nature of war itself was changing beyond imagining, commanders in the field were enabled to control huge troop movements or direct artillery fire onto targets from remote control emplacements or even aircraft spotters. The technology enabling generals to direct operations on fronts hundreds of miles away created a form of warfare of unprecedented scale and proportions. To most of Europe's young adult men about to be called to join the service of their country at the beginning of the last century, being able to communicate over great distances had an almost magical feel. Germany's scientists were in the forefront of this new communications revolution and Imperial Germany's government saw great possibilities in the telephone well before the war began. An ambitiously large network of telegraphic wires had been laid across Germany connecting important cities and, in particular, their military establishments. The High Command would be able to direct the great battles yet to come, using their newly installed telegraphic communications network, making the industrial scale of the First World War a possibility. This new technology would have far reaching effects on the war's fast-moving opening stages.
As the First World War began, initial actions were directed against communications networks in the shape of the great undersea cables connecting the major cities of the world. Cables were far more important to international communications at that time than radio telegraphy. The earliest cables were laid in the 1850s and the first cable links between Europe and America, or rather Canada, were made at that time. Complex cable networks linked the colonies of both the British and the German empires to their capitals and homelands; these links had been laid years before to transmit market and financial information to support the international trade of the world.
On the other hand, wireless technology was still emerging, although Germany, using the Nauen wireless station near Berlin, had just made her first long-range wireless transmission in 1913 to her station in Togo, German West Africa. The transmission was barely audible and, by comparison with a cable message that would have been clear and distinct, it seemed that wireless telegraphy still had some way to go. Britain had extended her own cable networks to every important part of her empire as a priority and owned, or at least controlled, much of the world's networks. She was also experimenting with wireless telegraphy and was slowly increasing the distance of global wireless transmissions. In 1910, communication was even made with an aeroplane in flight. Cable links, however, would initially prove more vulnerable to attack than wireless so, two years before the war started, the Committee of Imperial Defence planned a crucial action that determined the shape of the future signals intelligence war. A secret 'war reserve' standing order was issued by the British government to cut Germany's international undersea cables in the event of hostilities.
Just two days after war was declared, the cable ship Telconia slipped her moorings in Harwich on 5 August 1914 to steam out to a position near Emden on the German coast to dredge up, lift and cut five German telegraphic cables. The cables that were severed ran down the English Channel to connect with France, neutral Spain, Africa and to Germany's many friends in North and South America. A few days later, with second thoughts, the Telconia returned to dredge up and reel in many more thousands of feet of cable to ensure that the cable damage was irreparable. The Imperial German government could no longer send urgent cablegrams to their African colonies or embassies in many neutral countries around the world. One of the war's first military actions by the British was to raid and destroy the German cable station in Lomé in West Africa, isolating German cruisers on station in South Atlantic waters. Without the cable-based telegraphic communication to their bases, they would have to use wireless transmissions and potentially give their positions away to a listening enemy. The only cable left intact was the German-American line to Liberia and Brazil, and that was cut in 1915. All urgent messages to diplomatic, naval and military stations now had to be sent by powerful radio transmission from Nauen radio station. Soon radio researchers of the British Marconi Company began to pick up an increasing number of radio signals they identified as German naval communications. They immediately brought the text of those messages to senior officers at the Admiralty, who were initially at a loss as to what to do with them.
Transmissions began to be intercepted regularly by hastily erected listening posts on the east coast of England in the first days of the war. Listening, or 'Y', stations soon built up into a wide network of establishments dotted up and down the length of the English, Scottish and, later, Irish coasts. Intercepting German transmissions grew into a major surveillance system and the British also set up 'Y' stations down in the Mediterranean later in the war. The crew of the Telconia, and probably the British government, would not have realised that they had begun the work of Britain's code breakers.
Attacks on communications were not just limited to the British as German troops also raided a number of British and French cable stations, cutting overseas connections with India, as well as attacking cable stations on the East African coast which linked Britain's far flung empire. Baltic Sea cables were also severed by the Germans as they came to realise the importance of communications, so exchanges between Britain and her Russian allies became much more difficult.
Cutting Germany's cable communications fundamentally changed the signals intelligence battleground, although neither the Committee of Imperial Defence nor the German High Command could have foreseen its implications. German marine and, to some extent, military communications now became increasingly dependent on wireless transmissions. They were much slower in developing a listening network, but when they had realised that their cable network had been severed they began to develop a wireless telegraphy system to replace it. Nobody had yet realised how vulnerable electronic messages were to interception and decoding, or the part that SIGINT would play in shaping the the First World War.
Wireless Telegraphy Pioneers
Research into wireless telegraphy technology developed seriously in the 1800s, but early progress was mainly centred on the scientific aspects of this new mode of communication. It wasn't until later in the decade, after the scientific principles had been established, that it led to an increasing number of commercial products and services being created. Outstanding among the technology's pioneers, and destined to become a principal figure in the field, was an Italian named Guglielmo Marconi, who had begun to turn workbench-based experiments and pilot projects into working devices. He improved the transmission and reception of his wireless transmission device from a few hundred yards to miles and then hundreds and, finally, thousands of miles. He provided the expertise to build, operate and service the wireless telegraphy products he developed and, just as importantly, the business drive to create a market for them. Marconi rapidly grew from a radio 'nerd' working in his attic on a technology that no one had heard of, into a hard-headed business man negotiating with governments and building the Marconi international brand. He became a dominant force in the wireless telegraphy industry and, although he had many competitors, great and small, none made their mark with the public quite like he did. He and others in the field promoted wireless telegraphy on land and sea, and even in the air, in the first decades of the twentieth century until, by the 1930s, it began to be part of everyday life. The story of early wireless telegraphy was largely the story of Marconi because he brought wireless telegraphy to the market for good or ill. He himself said, 'have I done good in the world or have I added a menace?' The following pages seem to indicate that the industry that he did so much to build has proved a mixed but essential blessing to the military.
Marconi's interest in electro-radiation, or radio waves as they are now known, enabled him to get a place to study the emerging technology and its science at the University of Bologna in Italy. He was inspired by the research of Heinrich Hertz and others in Germany and from this he developed his own early experimental devices enabling him to design a wireless telegraphy system for sending signals a distance without wires. It consisted of a simple spark-producing transmitter, a wire as an aerial, a coherer receiver and a telegraphic key to operate the transmitter that sent the dots and dashes of Morse code, and a telegraphic register that recorded those Morse letters on a paper tape. His initial device could only receive signals over a short distance, but he proved that it worked and that the transmission and interception of Morse code was a feasible proposition.
By 1895 Marconi had lengthened the antennas of his sets, enabling him to transmit his messages for over a mile. He needed money to develop the capability of the technology, so he wrote to the Italian Post Office describing what his device could do – he was promptly invited to take himself off to a lunatic asylum. This rebuff pushed Marconi to take his wireless telegraphy device to London to seek interest and funding for his work as he spoke excellent English. He was able to demonstrate the machine to an amazed audience at the Post Office in London where a plaque on the wall of BT (British Telecoms) Centre still commemorates the first public transmission of wireless signals. This was followed by a number of demonstrations to the British government who invested in the new science. By March 1897, with the increased funding they gave him, he was able to transmit his signals for a distance of nearly 4 miles. This was followed by his first transmission across the English Channel to France in 1899. Later that same year, the American liner SS St Paul was the first ship to report her imminent arrival in Southampton using a Marconi wireless set at the Needles on the Isle of Wight while the ship was still almost 70 miles from port. Wireless telegraphy caught the interest of ship owners around the world but, in particular, the world's navies, who saw beyond its commercial use to the way it could be used in war. The naval manoeuvres of 1899 transmitted messages from ship to ship over a distance of almost 100 miles. The Royal Navy immediately placed an order for thirty-two of Marconi's wireless telegraphy (W/T) sets, and the Italian Navy followed suit with an order of twenty – Marconi was on his way. His next step was to span the Atlantic, so in December 1901 he set up his transmitters connected to a 500ft antennae supported by a kite in his attempt to span the ocean with his Morse code message. It consisted of the letter S in Morse transmitted as dot, dot, dot continuously, hoping that it would travel over 2,000 miles from Ireland to Newfoundland. There was some doubt at the time that the signal could be distinguished above the atmospheric noise, but when he announced his scientific advance the public believed him wholeheartedly and Marconi took his place in history.
A couple of years later, President Theodore Roosevelt was able to send greetings to King Edward VII transmitted from Marconi's Glace Bay Radio Station in Nova Scotia, marking the first wireless message transmitted from North America. A dramatic confirmation of the benefits of the new technology came in 1912 when the Titanic famously struck an iceberg at speed in the North Atlantic and began to sink. On the stricken liner the two radio operators, Jack Phillips and Harold McBride, who were Marconi International Marine Communications Company employees, sent their distress calls that summoned the RMS Carpathia to pick up the survivors of the tragedy. Marconi's Glace Bay Radio Station was the first to receive the Titanic's distress call and it was another of Marconi's men, David Sarnoff, who received and published the names of the survivors from the Carpathia via Marconi's wireless set. Wireless telegraphy suddenly became a 'must have' item in vessels of the world's navies and also most large liner and merchant ships that sailed the oceans of the globe. Marconi gave evidence concerning the use of wireless telegraphy in the Titanic disaster at the official inquiry in 1912 recommending wireless telegraphy procedures that he felt were needed during emergencies at sea. The British Postmaster General stated afterwards: 'Those that have been saved in the disaster have been saved by one man, Mr. Marconi and his marvelous invention.' It is sure that without the SOS wireless distress signals that the Carpathia received from the Titanic its sinking would not have been just a disaster but probably also the world's greatest maritime mystery. The great liner would have disappeared among the ice flows of the dark North Atlantic with all on board without trace or sound.
Wireless messages could be received by anyone with the right equipment and the new means of communication was to prove a boon to mankind in many ways. The blessing extended to the military, which needed to communicate confidentially with its men on the ground using coded methods of transmission. Codes and ciphers have made it possible to maintain secrecy in messages and the military were able to send that coded form in Morse to their controllers, whether in London or Moscow. The code breakers were yet to arrive on the scene.
The History of Codes
Encryption of messages into coded form is a science and, like so many other scientific disciplines, has its roots in the culture of ancient Greece. In the Greek language kryptos means 'secret' and graphos means 'writing'; thus we have the science of cryptography. There are earlier examples of codes among the ancient Egyptian, Hebrew and Asian scholars, but the main tradition of European encryption seems to have come down from the ancient Greeks and was later expanded by the Romans. Coded messages have been used, principally by military men, through the centuries. The first of them recorded their coded messages by stylus and then on papyrus, and in later centuries quill pens and parchment. Within living memory, pen nibs dipped in inkwells inscribed copperplate writing on to paper in laborious hand-written text. Now, of course, it is the universal computer that records and even solves the code using methods built on algorithmic principles devised by the ancients. The science of cryptography 'stands on the shoulders of giants', like so many of our other intellectual and scientific achievements, therefore a bit of cryptographic history is needed to help the reader appreciate how the 'Black Art' of encoding and decipherment of messages has developed and some of the ways it has affected our modern world.
In 405 BC the Greek General Lysander of Sparta was said to have received a coded message called a scytale in a servant's belt that enabled him to surprise the Athenian Navy at Aegospotami. The encrypted message was read by winding the belt around a wooden baton which the messenger also carried with him to help the general reveal the hidden text. When Lysander was warned of the Athenian threat he immediately set sail to surprise and defeat them. Alexander the Great used codes and even devised the first postal censorship system while besieging General Memnon of Rhodes, who was fighting for the Persian King Darius at Halicarnassus in ancient Greece. Alexander wanted to know the state of his troops' morale, so he encouraged his soldiers to write home and then intercepted the courier to read the letters to see how his men truly felt about their army's conditions. By reading their private correspondence, he was able to identify many problems and grievances which he was able to put right, and also to identify the unreliable men in the ranks whom he sent home. Other Greek military men devised an encryption method that substituted letters for numbers using a table called the Polybius Square (below). Using the table shown as an algorithm, the key enables the reader to decode a text in which the letter A is represented as 11, B is 12 and so on. Thus enciphering the word 'war' using the table gives the coding of 52 11 42. A similar code to this based on the Polybius Square was still being used in the trenches of Northern France in the First World War over 2,000 years later.
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Excerpted from SIGINT by Peter Matthews. Copyright © 2013 Peter Matthews. Excerpted by permission of The History Press.
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