CHAPTER 24
We are surrounded by a world of secret communications . . .
—Eric Cole, Hiding in Plain Sight
America’s intelligence services (CIA, FBI, and some military elements) recruited foreign spies with the access and opportunity to procure (which is to say, steal) secret information considered vital to U.S. national security. However, without an ability to communicate securely with his handler, the spy and his purloined secrets are worthless. Spies were most vulnerable to being caught not while procuring the information, but when attempting to pass their secrets to a third party. Every agent required his own tailored covcom that fit his circumstances and the kind of information he collected. A film cassette filled with photographs of classified memos represented a different covcom problem than passing printed pages of a radar system’s operating manual or the actual circuit board from a missile guidance system.1 Information exchanges between agent and handler must be both secure and secret. Codes and ciphers provide levels of security while digital steganography hides the encrypted information in a cloak of electronic invisibility.2
In the last half of the twentieth century the “Holy Grail” of covcom was envisioned as a secure system of two-way, reliable, on-demand exchange of voice, text, and data 24/7 from and to any location. The message need not necessarily be encrypted, but the communication process must present a low probability of detection and interception. Once concluded, the exchange would leave no record of having occurred or any telltale electronic footprint. Such a system would be used “from anywhere to anywhere” in the world for an agent to “talk” to his handler, CIA Headquarters, or even the President of the United States.
Every CIA covcom system, from the personal meeting between handler and agent to a multimillion-dollar satellite link between an agent and the DCI, consisted of three primary segments: the field set (what the agent used either to receive or send), the transmission backbone (such as shortwave, high-frequency broadcasts that carried the message), and the receiving element. Personal meetings between agent and handler required comparatively less technology while covcom through satellites was dependent on technology. 3 Regardless of the system, each involved integrating whatever special devices were needed with sound tradecraft at every stage of system development, delivery, and, in the case of the agent, concealment of incriminating equipment. The fewer pieces of spy gear in the agent’s possession and the fewer unnatural acts he had to perform operationally, the lower was his risk of being detected.4
Through the years, the CIA’s Office of Communications, Office of Research and Development, Office of Development and Engineering, and Office of Technical Service each pursued some element of covcom’s Holy Grail. Their efforts resulted in the deployment of successive generations of technically sophisticated gear that advanced one or more of the following imperatives: obtain more timely information, improve security, pack the maximum amount of information into an exchange, and deliver intelligence ever more quickly to the end user.
When selecting a covert communications system, the case officer considered factors such as the agent’s lifestyle, profession, ability to travel abroad, and risk tolerance. He estimated how frequently the covcom would be used, the size and aggressiveness of the local counterintelligence service, level of surveillance directed against the handler, and the number and types of covcom systems already operating in the area. Regardless of the variables, two general categories of covcom occurred between agent and handler: personal and impersonal. Each category of covcom has advantages as well as risks.
Personal meetings between an agent and handler (often a U.S. official) represent the riskiest form of covcom. Hostile governments conducted routine surveillance of foreign diplomats under the assumption that some of them were actually intelligence officers operating under official cover. Persons suspected of having an intelligence affiliation were systematically surveilled to detect signs of clandestine activities such as clearing and filling dead drops or meeting an agent. The agent, unless already under investigation, was less likely than the American to be under surveillance, but if observed in an unauthorized meeting with a foreign official, immediately was suspect and placed under surveillance.
Despite the risk, face-to-face meetings were frequently a preferred means of communication with agents. Exchange of materials was assured, conversations could address urgent issues, conflicts could be ironed out, and the agent’s morale given a boost. During personal meetings, the handler was always alert for changes in the agent’s attitude, motivation, personality, and health. He was able to conduct hands-on agent training, modify requirements, change operational plans, and gauge firsthand the extent of any counterintelligence problems.5
Given the inherent risks, however, personal meetings in denied areas were kept to a minimum, carefully planned, and never conducted without a specific reason. The handler was always prepared for the contingencies necessary to maintain the security of the operation; meeting times, duration, and locations were selected to provide a plausible cover story for both handler and agent in case they were observed. The agenda for the meeting was scripted in advance; initial greetings were immediately followed by a standard question, “How much time do you have?” Next on the script was to agree on arrangements for the next meeting should they be interrupted.6
To minimize the counterintelligence exposure of an agent being spotted during a personal meeting, the CIA developed techniques known as “brief encounters.” These involved a personal contact between the agent and handler, but minimized the length of time required for an exchange of material. In 1958, the CIA Chief of Station in Prague, Haviland Smith, developed the technique of a “brush contact” or “brush pass” while providing tradecraft training in New York City to a Czech agent.7 Smith noticed that the agent was reluctant to leave his package of secrets in a dead drop for fear it would be discovered and traced back to him. As an alternative, Smith had the agent stand just inside the entrance to the Grand Central Terminal where a person entering had the option of proceeding straight ahead to the old Biltmore Hotel or turning right and descending down a flight of stairs to the subway.
Smith knew that at that point he would be momentarily out of sight of any trailing surveillance. If an agent was waiting at the top of the stairs and just inside the entrance, Smith could pass a newspaper to the agent, who would quickly turn around and head down into the subway while Smith proceeded straight ahead into the hotel. It worked so well that, in a training exercise, even when the surveillance team was looking for the move, as long as they were following Smith from behind, the pass could not be detected.8Only in the unlikely chance that the hostile surveillance team had somehow anticipated Smith’s travel path and arrived ahead of him could the exchange be spotted. The counterintelligence surveillance team was never certain where Smith, who varied his routes and timing, was going and could not “set up” on him in advance. Case officers and techs identified similar locations in cities around the world where the same technique could be used.9
In a variation of the brush pass, the moving-car delivery technique allowed an agent to drop a package covertly into the handler’s slowly moving vehicle through an open window.10 The travel route selected by the handler was consistent with his normal evening routine and included a number of right-hand turns on dimly lit side streets. Following each right-hand turn, the handler’s vehicle was out of sight of the trailing surveillance vehicle for a few seconds; the CIA referred to this brief window of time as being “in the gap.”11 The agent was instructed to stand in the shadows at the corner and watch for the handler’s car to complete the turn. When the car was briefly out of sight or in the gap just following the turn, the driver would dim the car’s lights as a signal to the agent. The agent then stepped to the curb and dropped the package through the open window. Immediately after making the exchange, the agent receded into the shadows and remained motionless until the trailing surveillance vehicle passed. A concealment cavity built into the car’s dashboard or floor mat was used to hide the package until the driver and vehicle returned to a safe compound.
A higher-risk variation of the moving-car delivery occurred when the agent and handler both drove vehicles to the same traffic signal and pulled up alongside each other. With the agent’s car on the right and the passenger window of the handler’s car opened, the agent tossed the package into the empty seat. A moving-car exchange required thorough planning and excellent timing, but when executed properly was virtually undetectable.
Impersonal communications, those not requiring face-to-face meetings, were employed when personal meetings were excessively risky or impossible. Impersonal communications separated the agent and handler by time, space, or location.12 During the initial phases of agent recruitment, face-to-face meetings between the case officer and target were often necessary, but would be phased out when the target accepted the clandestine nature of the relationship. The more hostile the operating environment, the greater was the need to shift to using impersonal communications to protect the agent. 13
Impersonal communications using either dead drops or electronic devices offered advantages to the agent and handler and when properly executed were difficult for counterintelligence to detect. Dead drops avoided the necessity for the agent to possess an electronic transmission device, but required time-consuming surveillance detection runs by the handler. Conversely, electronic exchanges usually obviated the requirement for lengthy surveillance detection on runs but the technology could fail, and in its early years of use, often did. Other disadvantages to using impersonal communications included the handler being unable to directly assess the emotional and physical condition of the agent, and the communication stream being accidentally or intentionally interrupted or intercepted. Agents, as in the case of A. G. Tolkachev, could also decide the electronic gadget was unwieldy and stop using it, or that the amount of information passed during any one electronic transmission was too limited.14
Dead drops are the most commonly used and most secure form of impersonal communication.15 Dead drops enable agent and handler to exchange messages, correspondence, documents, film cassettes, money, requirements, and instructions without a direct encounter. Dead drops were “timed operations” in which the dropped package remained in a location for only a short time until retrieved by either the agent or handler.
Dead drop sites are selected from locations to which both the agent and the handler have normal access. Public sites for dead drops ranged from parks and nature trails to stairwells, parking garages, and elevators. Site selection varied depending on the country in which the operation was taking place and the circumstances surrounding the agent. Examples might include a library that contained a shelf of little-used books or the door of a mosque where shoes of either the agent or handler would serve as the container for the material being exchanged. Private areas, such as social clubs and health clubs, were also used if they contained obscured areas where drops could be left without notice.
The ideal dead drop site was used only once, was in a location that could be precisely communicated to the agent, and provided speed of access for both the agent and handler. The site should also provide privacy so that it could be loaded and emptied without the agent and handler being observed.16 Finally, the location would be selected so that both the handler and the agent had plausible reason to be at the site and in a setting where the concealment would naturally pass unnoticed. A case officer from the 1970s who handled Polish officer Ryszard Kuklinski observed, “every CIA officer serving in a denied area should have a dog.” Even in areas with constant and unfriendly surveillance, the necessity of taking the dog for walks provided excellent cover for carrying out operational acts involving signal sites and dead drops .17
In most capital cities, such as Moscow, Vienna, Paris, Washington, and Berlin, the number of “pristine sites” that met operational requirements for dead drops was limited, since thousands of intelligence officers from different countries had worked the same areas for decades. As a result, there was continuous pressure to identify new sites for future operational use. Techs and case officers shared the responsibility to find, photograph, sketch, and maintain inventories of valid sites. The difficulty in doing so was compounded because all signal and drop sites possess the same general attributes. In response, alert counterintelligence officers could set up an observation post at likely locations and patiently wait for them to be used. Nevertheless, the value of dead drops, despite their complexity and limitations, makes them a primary tool of every professional intelligence service.
Signal sites were among several methods used to initiate a communications sequence between the agent and handler. Signals of some type usually preceded or concluded an operation and were normally linked to a specific meeting place or dead drop location. For example, a signal left at site “Alpha” may initiate a drop at site “Bravo” or a meeting at a designated park bench.
Signal sites were usually located in public places, away from the actual drop site, and positioned so that the agent or a designated observer passed them regularly. Signposts, telephone poles, bridge abutments, and mailboxes were among the sites typically used to place a signal. Visual signal marks were made using postage stamps, white adhesive tape, masking tape, colored thumbtacks, colored adhesive-backed stickers, colored chalk, lipstick, and even crushed cigarette packs. A precisely placed soft drink can is readily visible to a passing car, bus, or pedestrian and becomes an effective signal. The positioning of the tape, or the color of the thumbtack, chalk, or other signal could also send a danger signal or initiate an escape sequence.18 Even if the chalk mark was observed, its meaning was unknown to anyone other than the agent and handler.
Usually after placing the material at a dead drop site, a signal was left to communicate that the drop had been “loaded.” The person unloading the drop would then confirm the presence of the signal before proceeding to the site. Once he had retrieved the materials, or “cleared the drop,” a final signal might be left to communicate that the package was safe and the operation concluded. The absence of valid signals indicated a problem and forestalled either the agent or handler from approaching the site.19
Priority was always given to creating a safe and secure means for the agent to both send and receive messages. Signals were forms of codes that used symbols to communicate longer meanings. Other types of signal techniques included a “car park signal” based on the direction a car was parked, its parking location, or the direction its wheels were turned, and a “window signal” that used the raised or lowered position of a window or drapes and blinds (open, partially open, or closed) to send a message. The position of a potted plant visible to passersby could also have been a signal depending on where it was positioned.
Calls placed through the public telephone system, while subject to monitoring, could be safely used to send signals. An example was a “silent call” or “dead telephone” signal that was received at the agent’s home at a predetermined time. The caller, using a public phone in a nonalerting location, said nothing but remained on the line for a set number of seconds before hanging up. To the agent the call had meaning, but to anyone monitoring the agent’s telephone lines the call had no significance. Even if it was traced to the public telephone, it could not be linked to a case officer. When executed carefully, and used infrequently, the silent call or other wordless signals were almost impossible for an adversary to decode.
Other impersonal exchanges may be undertaken using public systems such as the postal service, telephone, telegraph, newspapers, radio transmissions, and the Internet. Within public systems, covert communications are mixed with the billions of daily telephone calls, letters, postcards, telegrams, newspaper ads, e-mails, Web postings, and instant-messaging transmissions.
When personal meetings were required, a technique known as a “visual recognition signal” could safely send a coded message from the agent to handler prior to any personal contact. Typically, the agent would be instructed to appear at a busy intersection at a prearranged date and time wearing clothing whose color was meaningful to the handler, but not alertingto counterintelligence if he was under surveillance. Anyone aware of the operation and familiar with the agent’s photo and instructions could observe from a distance to see if a properly attired individual appeared at the established time.
Secret writing has existed for at least 2,000 years and predates the establishment of the first European postal systems.20 Letters and postcards mailed by an agent to an accommodation address outside the country of origin were commonly used throughout the twentieth century to conceal secret writing. The technique represented an early form of steganography in which the goal was to mask the existence of a communication. The CIA used three forms of secret writing: wet systems, dry systems, and microdots .21
Wet systems used special inks that became invisible on the paper after the writing dried; the hidden message became visible again only when a reagent matched to the ink was applied. As a simple example lemon juice was used to constitute an ink and the heat from an electric light bulb or candle as the reagent. OTS packaged dehydrated heat-sensitive inks in a variety of disguised forms. Aspirin tablets made good candidates as concealment hosts because they were commonly carried and could be stored in a medicine cabinet at the agent’s home without attracting attention; when dissolved in water the pills created the ink. The agent dipped a sharpened wooden stylus or toothpick into the liquid and wrote on bond paper he had prepared by rubbing with a soft cloth in all four directions. Agents were instructed to write on paper placed on glass to prevent indentations and minimize the disturbance to the fibers in the paper. After the letter had been composed and the ink dried, the agent would again rub the paper in all four directions to eliminate any traces of the message in the paper’s fibers. Later the letter would be steamed and placed inside the pages of a thick book to dry.22 Agents would prepare a cover letter over the secret writing for mailing to an accommodation address outside of their home country.23
While it was most often used as an “agent-send” system, in some instances agents also received instructions by secret writing. To eliminate the complexity of developing the writing and minimize the amount of potentially incriminating reagents in an agent’s possession, OTS often recommended the “scorch method.” Polish military officer Ryszard Kuklinski received innocuous letters that contained hidden messages that became legible only when they were scorched with a household iron.24 With thousands of potential combinations of inks and reagents to select from, OTS produced hundreds of such systems. In an emergency, however, diluted blood, semen, and even plain water could be used as an invisible ink.25
Two weaknesses of wet systems were the requirement for the agent to possess the special ink and the near impossibility of removing all traces of damage to the paper’s fibers. Even if the secret ink was not detected, under close scrutiny the damage to the fibers of the paper sometimes became noticeable.
Dry systems began appearing in the late 1950s as a variation of carbon typing paper. Chemists impregnated special papers with small amounts of chemicals and bound them into common items like writing journals, endpapers of books, or the last few pages of notepaper in a checkbook. The agent would sandwich three pieces of bond paper on top of a piece of glass. The top and bottom papers were blank while the middle page was the special “carbon paper.” The agent wrote the operational message on the top page and the secret chemicals were transferred onto the bottom page. These dry systems quickly became the preferred method of secret writing in the 1960s.
Former MI6 officer Richard Tomlinson described a modern dry system developed by the British service:
Using the Pentel Rollerball pen provided by Technical and Operations Support, Secret Writing, [I] wrote up the intelligence in block capitals in the standard format of a CX [raw intelligence] report. . . . It all fitted onto one page of A4 paper from my pad of water-soluble paper. Putting the sheet faceup on the bedside locker, I laid a sheet of ordinary A4 paper over it, then on top of both of them. . . . Five minutes was enough for the imprint transfer to the ordinary A4. The sheet of water-soluble paper went into the toilet bowl, and in seconds, all that was left was a translucent scum on the surface of the water that I quickly flushed away. Back in the bedroom, I took the sheet of A4, folded it into a brown manila envelope, and taped it into the inside of a copy of the Gazzetta dello Sport.26
The simple but effective system eliminated the concern of the officer being detected with spy gear since the Pentel Rollerball was commercially available and uncompromising.27 The technique allowed the agent to see what he was writing before making the offset copy. Tomlinson observed that “off-setis now used routinely by MI6 officers in the field for writing up intelligence notes after debriefing agents, and is also issued to a few highly trustworthy agents, but is considered too secret to be shared with the liaison services such as the CIA.”28
Tomlinson also described a method for developing the Pentel secret writing:
At the back of the pad, I ripped out the fifth-to-last page, took it to the bathroom, placed it on the plastic lid of the toilet seat, and removed a bottle of Ralph Lauren Polo Sport aftershave from my sponge bag. Moistening a small wad of cotton with the doctored cologne, I slowly and methodically wiped it over the surface of the paper. [The message] started to appear, darkening to a deep pink. Using the hotel hairdryer, I carefully dried the damp sheet, trying not to wrinkle it too much and drying away the strong smell of perfume. It now looked a normal letter, though in a slightly peculiar dark red ink.29
Microdots and other reduced-image techniques represented a third form of secret writing. A microdot was an optical reduction of a page of text or photographic negative to a size that was illegible without intense magnification. Commonly defined, microdots were less than 1mm square and required optical magnification of at least 100× to be read. The microdot’s larger cousin, a macrodot, created with similar photographic reduction processes, was considered much less secure. Operational advantages to using microdots included their tiny size, which made it possible to conceal the dot inside a variety of hosts, and convenience of delivery to virtually anyplace in the world using public systems such as the postal service.
CIA case officers received familiarization training in microdot communications, but making and burying an operational dot required assistance from an OTS specialist possessing both the necessary equipment and practiced skills. Dots were usually a last choice for agent covcom.
There were also operational disadvantages to using microdots:
• The production and burying of a dot by the originator was exacting and time-consuming.
• Microdots were often so well concealed they were difficult for the agent to find in the host letter or document. When located, the microdot had to be carefully dug out and properly positioned for reading.
• Microdots required special optical viewers with sufficient magnification to make the message legible. Other dots had to be redeveloped before they could be read.
• Microdots were usable primarily as a one-way agent-receive system. The lack of agent photographic skills, equipment, and training for microdot preparation most often precluded their use as an agent-send system.
• Microdot preparation usually required specialized photography equipment that, if discovered in an agent’s possession, would arouse suspicion of espionage.
For additional secrecy, microdots could be rendered invisible by bleaching in a small amount of diluted iodine before use; the process was reversed by redeveloping the dot after being received. The tiny bleached dot could be buried behind a postage stamp, the flap of a letter, inside the thickness of a postcard, or underneath a raised typed letter on a single sheet of paper. TSD manufactured a special “slitter” for slicing an opening on a postcard or raising a tiny flap on a piece of paper so that a microdot could be inserted.30 Once placed inside, the dot was sealed in place with a dab of egg white, carefully rolled with the curved edge of a glass to pick up excess “glue,” and placed beneath a stack of books to dry. When properly prepared a microdot could be buried so effectively that it defied detection, even when a counterintelligence service was alerted and searching for it. Often, ensuring that the microdot could be found by the agent at its destination was a greater challenge than finding ways to conceal and transport the dots.31
After an agent dug out his microdot, he required a reader of sufficient power to read the message. Since a microscope might appear out of place inside the living quarters of many agents, OTS issued three small, concealable microdot readers. The smallest was the “bullet” lens also known as the Stanhope lens.32 This tiny lens, a thin glass rod (3mm × 6.8mm) slightly larger than a pencil lead, had a spherical convex curvature on one of its surfaces, and a polished plane surface on the opposite side. The microdot could be moistened with saliva and affixed on the flat side of the lens; the user held the opposite side next to the eye. The bullet lens was capable of magnifying a microdot more than thirty times.33
TSS bought a hundred Stanhope lenses in the early 1950s from a novelty company only to discover that they came preloaded with sexy pinup photos of American starlets. The potentially offensive images were re-movedbefore the viewer was issued to agents and the lens required no further modification. The tiny size of the bullet lens enabled it to be readily concealed and transported inside a cigarette or bottle of ink, or sewn into the seam of a jacket or dress. One case officer carried the lens in the corner of his eye. Operationally the bullet lens was so small that the care and skill required to position the dot and view the message made it unpopular with agents.
The Stanhope lens, shown against a penny, was one type of microdot reader issued by OTS.
Despite its deficiencies, the bullet lens proved invaluable for some operations. In 1969, the CIA recruited a middle-aged Cantonese-speaking woman to serve as a courier into southern China. The courier, who lived in Hong Kong, had immediate family members living in Canton whom she partially supported by her modest jade and semiprecious stones shop. Among her family members was a first cousin, also a CIA asset, with connections to a prodemocracy intellectual group that produced antigovernment publications and leaflets. The CIA was supporting the effort as a covert action and used microdots embedded in personal letters and postcards as the primary means of covert communication. When the agent lost the last of his microdot readers, the covcom link collapsed.
The case officer appealed to the courier to take several new bullet lens readers, each approximately the size of grain of rice, to her cousin. Recognizing that border checks for anyone entering China were intense, with pat downs and body cavity searches common, the case officer suggested the lens be embedded into the gauze of a Band-Aid that covered an active sore on the courier’s foot.
The proposal was met with scorn. From the agent’s perspective, the concealment was far too dangerous because the hard lens might be felt through the gauze. If discovered, the penalty would be severe. The agent agreed to take one of the lenses but said she would think of a much better concealment by their next meeting.
A week later, as the two were meeting, the agent unexpectedly dumped on the table a catty (680 grams) of dried fish, each fish about the size of a small minnow. The tabletop was covered with dozens of little fish.
“Find it,” she ordered the case officer.
“What?” he replied.
“The lens is with the fish, you find it.” Her tone was not amused.
The case officer looked at the fish. All were the same, dried, and some nearly translucent. He picked up several and examined. There was no way he could even imagine where the lens might be.
“I can’t.”
The agent began picking up fish and rubbing each between her fingers.
After handling several, she announced, “Here it is.” She peeled off the dry skin and tore open the fish. Out popped the lens.
The lens had been inserted through the mouth into the belly of fish. The expandable cavity was long and large enough to hold the lens but the lens itself was not so thick as to distort the fish’s appearance.
“This will be a lot safer than your Band-Aid. They will never inspect these fish which are like what everyone takes into China,” the courier asserted.
The case officer could only agree and thought of lyrics from the musical The King and I: “When you become a teacher, by your students you’ll be taught.” In this instance, however, when you become a case officer, by your asset you will be taught.
The operation was successful and the lens reached the agent as planned.
TSD produced a more user-friendly microdot viewer, the “114 Reader,” that was about the size of two pencil erasers. It unscrewed so that the dot could be placed between the two halves and viewed. The superior optics and larger size of the viewer made it more popular with agents but also more difficult to conceal.
The largest of the CIA’s microdot viewers was the “little telescope” (about the size of an unfiltered cigarette) with an internal telescoping section for magnification up to 150 times. The viewer was more powerful and easier for agents to use than its predecessors, but it was much larger. If detected it was clearly recognizable as a piece of spy gear, but the little telescope was still small enough to be concealed in a pack of cigarettes or a modified fountain pen.
In 1983, the CIA recruited Soviet Colonel Vladimir Mikhailovich Vasilyev in Budapest and assigned the codename GTACCORD. To communicate with him after his return to Moscow, OTS perfected a new technique of sending messages using a Hewlett-Packard computerized laser-engraver. The technique allowed the CIA to etch a microscopic message into the black borders of features inside the February 1983 issue of National Geographic magazine.34 The hidden message in the ruled line was invisible to the unaided eye, though readable with a 30x magnifier.
The laser-engraver burned away microns of ink to leave a message that had characteristics of a microdot but did not require the additional stages of development and precise handling. By etching the message on an advertisement in a popular magazine to which GTACCORD had normal access, there was no link back to a specific agent should the presence of the message be detected. The secret message contained the internal commo plan for GTACCORD to contact CIA. It read: “Your package should always be in a waterproof wrapper placed inside a dirty, oily rag tied with string . . .”35
The commo plan worked. Colonel Vasilyev spied for the United States for three years until he was betrayed by CIA officers Edward Lee Howard and Aldrich Ames in 1984 and 1985. Vasilyev was arrested in 1986 and executed in 1987.36
One laser-engraving effort left an enduring olfactory memory with the OTS techs. In this operation, the covert message was placed on a border line of an advertisement for fancy chocolates in a gourmet magazine. The advertisement was printed with newly developed “chocolate-scented ink” and when the laser-engraver began burning the ink to embed the message, the entire OTS lab took on the smell of fresh-baked chocolate chip cookies.
Another reduced-image technique involved photography that used a sensitive, fragile emulsion layer of film. This plastic wrap-like substance could be separated from the thicker cellulose base of some types of film. Called “soft film” by the KGB, it was one of the most usable methods for clandestine communication even before World War II and saw use extensively throughout the Cold War.37
In the 1980s, OTS developed laser-engraving for clandestine communication. This was used by CIA agent Colonel Vladimir Vasilyev in Moscow. Left: Cover of National Geographic magazine. Right: Inside page of the magazine showing location of the line containing micro-engraving, mid-1980s.
Typically, a frame of soft film contained the image of a single page of text, which could be produced in a variety of sizes. Although a frame was much larger than a microdot and more vulnerable to detection, it was much easier for the agent to use. Larger examples could be disguised as photo protectors inside a man’s wallet or the shiny coating of a postcard such as was used by George Saxe’s agent in the late 1960s. Pieces of the pliable film could be rolled into tiny cylinders as small as the size of a matchstick, concealed in such varied household items as a hollow pencil or a ballpoint pen refill, or sewn into the lining of clothing, and then read using a standard magnifying glass.
Kalvar, a commercial product developed as an alternative to traditional microfilm, represented one of the OTS’s most successful special films for reduced-image photography. The company that first manufactured it ceased operations in 1979 but other firms continued making Kalvar for OTS.38 In operational use, the advantage of Kalvar was that it could be handled and processed in normal room light, did not require special chemicals, and was developed in boiling water.39
Ultrathin-base (UTB) films were used for the subminiature cameras provided to agents and officers for clandestine photography; the thinner backing (base) allowed a standard film cassette to contain hundreds of exposures and increased the volume of information passed in a dead drop exchange. UTB film could not withstand the rigors of passing through automated processing and developing equipment, however, and required OTS techs to hand roll, spool, and later process the exposed film at remote field photo labs. The combination of UTB film and reliable OTS subminiature cameras produced some of CIA’s best Cold War intelligence.
For further enhancement of operational security for clandestine photography, TSD developed special processing film (SPR) that looked and performed exactly like a standard cassette of 35mm film. However, after the film was exposed, any attempt to develop the images by a person without knowledge of the counterintuitive steps required, would result in a completely black or transparent strip on any part of the film that was SPR treated. The advantage of SPR film was that the agent could photograph secret documents and keep the film in his camera with the knowledge that even if it should be searched and the film processed, the compromising evidence on the roll would not be discovered.
During operational meetings, both the agent and handler would make and retain written notes for reminders, specific instructions, phone numbers, and names. Because the notes were sensitive and potentially compromising, a means to destroy the notes quickly and thoroughly, if necessary, was required. OTS developed a variety of secure note-taking capabilities for protecting such information.
Water-soluble paper was produced by a small CIA-owned paper-making machine and cut and bound into forms required by operations. Visually, the special paper resembled thin copy or tracing paper although it could also be made in a variety of weights. When dropped in water or any other liquid, the paper, together with the ink or pencil markings, dissolved immediately. Splashing water on the soluble paper left an instant gooey remainder that could not be restored to recover the original writing.
The CIA agent Ryszard Kuklinski had a pad of water-soluble paper onto which he copied his exfiltration plan to study and memorize. The original plan was passed to Kuklinski on a microfilm that he kept hidden. However, by copying the plan on water-soluble paper and taping it beneath his kitchen cabinet, it was more readily accessible and Kuklinski felt confident he could destroy the information quickly if necessary by dropping it into a waiting pan of water in the kitchen sink.40
A case officer driving through a city to identify new dead drop and signal sites would need a way to make notes but also required a quick destruction method if stopped by local police or involved in an automobile accident. Water-soluble paper and a handy bottle of water provided the solution. If a problem arose, the water could be doused on the notes, reducing them to a mushy residue.
An alternative was flash paper, a form of nitrocellulose that burned quickly and completely with a bright flame without smoke or ash. Any printing or writing on the paper would be destroyed when ignited. Because agents and case officers often smoked, a lit cigarette could be used to ignite flash paper carrying operational notes, one-time pads, communications plans, and other sensitive material. The effectiveness of instant destruction was offset by the reality that the “flash” of the ignited flash paper would assuredly attract attention, limiting its operational use.
Another option available to case officers was the so-called more-or-less-invisible (MLI) writing instruments developed by the chemists in OTS’s secret-writing program. The abundance of ballpoint pens and other plastic products in the 1960s led the scientists to coat commonly available plastic items with special chemicals. The treated items, when used as a writing instrument, left invisible traces of the chemical residue on paper that could subsequently be developed and read. While a casual observer would see nothing on the paper, professional techniques could detect the presence of secret writing.
Only imagination limited the variety of plastic that could be used. MLI chemistry could be applied to eyeglass frames, caps on ballpoint pens, plastic key fobs, credit cards, and even the plastic toothpick on commercial models of the Swiss Army knife. Case officers using an MLI device to “write” invisibly on a piece of paper could carry those safely until returning to the station where a tech developed the notes.
TSD answered a request from the Directorate of Operations in the early 1970s to provide a secure system that would allow a case officer or tech to record and store operational notes on a tape recorder. OTS modified small commercial Sony stereo tape recorders by adding an additional, or “third track” recording head. In use, the tape recorder would function normally to play tapes filled with local music in two channels of stereo. When an officer wanted to record operational notes, he activated a switch OTS had built into the recorder and turned on the secret recording head for the third track. The audio would be recorded on the tape, but on a track that was unreadable on any nonmodified tape recorder, and only an operational listener would know how to activate the switch to listen to the third track.
In a variation on the concept, the clandestine communication branch of MI6 created a similar covert system. Former MI6 officer Richard Tomlinson described it:
The essential feature of these gadgets is that they are noncompromising, i.e., they are identical or virtually indistinguishable from commercially available equipment. Pettle recorders were particularly ingenious. Any normal audiocassette has two tracks running parallel to each other, one for each side of the cassette. Pettle recorders exploit the unused part of the magnetic tape, which lies between the two strips. [We observed] an ordinary personal stereo, which played and recorded on both sides of the tape like an ordinary machine. But turning it upside down tripped a microswitch so that pressing the STOP and RECORD buttons together made the machine record over the central track, while pressing STOP and PLAY together made it play back the recording.41
Codes and ciphers play essential roles in successful covert communications systems. A code obscures the meaning of a message of any kind by substituting words, numbers, or symbols for plaintext (the unencrypted text of the message). A single symbol could represent an idea or an entire message. The signals made with chalk, lipstick, or a thumbtack to initiate a dead drop sequence were examples of codes while the message concealed inside the dead drop had the added protection of a cipher. A cipher represented a particular type of code in which numbers and letters were systematically substituted according to a prearranged plan. Ciphers used a key to convert the plaintext message.
Probably no piece of spy gear was more often issued or more reliable than the one-time pad. OTPs, the only cipher system that was known to be theoretically unbreakable, were composed of one or more pages filled with random numbers arranged in groups of five.42 Only two copies of an OTP were produced—one copy for the agent and one for the handler. To maintain the security of communications, the OTP page and all notes from using it were to be destroyed by the agent as soon as the working session was completed.
OTPs had great advantages and were praised by both agents and handlers. One OTS tech who ran operations in Moscow for two decades stated, “OTPs didn’t let us down. They didn’t leave you or the agent wondering if the communication was secure.” OTPs proved to be the best covcom security available during most of the Cold War; agents had immense confidence in the security of the OTP system because they understood that even if the message was discovered, its contents would be illegible and there was no link to the agent. The difficulty with the system was that OTPs were immediately recognized as spy gear if discovered, and since only used once, they had to be constantly resupplied through dead drops.
The one-way voice link described a covert communication system that transmitted messages to an agent’s unmodified shortwave radio using the high-frequency shortwave bands between 3 and 30 MHz at a predetermined time, date, and frequency contained in their communications plan. The transmissions were contained in a series of repeated random number sequences and could only be deciphered using the agent’s one-time pad. If proper tradecraft was practiced and instructions were precisely followed, an OWVL transmission was considered unbreakable. The agent was able to use OWVL only to receive communications, but it had many advantages over secret writing or agent meetings. OWVL required no spy gear except a one-time pad, was generally reliable and repeatable, and precluded surveillance. As long as the agent’s cover could justify possessing a shortwave radio and he was not under technical surveillance, high-frequency OWVL was a secure and preferred system for the CIA during the Cold War.43
The OWVL transmission consisted of a series of numbers, usually in groups of four or five. During the 1950s and 1960s, they were read by a man or woman, and in later years produced by an electronically generated voice.44 The numbers could be spoken in any language, usually timed to begin on the hour, quarter hour, or half hour, and were repeated hours or days later on the same or a different frequency.45
Facilities with giant antenna farms to broadcast OWVL signals to every country of operational interest were positioned at strategic locations in the United States and abroad. The sites served the dual purpose of handling CIA staff communications traffic as well messages for agents.
In the late 1970s, OTS and the Office of Communications began upgrading the OWVL system with the development of the interim one-way link (IOWL). This used the same broadcast stations and network as OWVL, but the agent’s commercial shortwave radio was replaced by a dedicated IOWL receiver. The self-contained miniature piece of spy gear was a black box about the size of a pack of cigarettes and half as deep, including the internal battery. Its size made concealment relatively easy and it could be plugged into a standard speaker or operated with headphones. The primary benefit to the agent was the speed of receiving a message; the numbers were transmitted at higher speeds and then stored internally in the receiver to be recalled later. Decreasing the time an agent had to spend performing the covert activity of listening to and transcribing shortwave transmissions improved security and his efficiency; messages that previously had required the agent to listen and copy for an hour could be received in ten minutes. IOWL required the agent to possess and hide another piece of spy gear, but because it was technically equal to OWVL and offered advances in reception speed and an improvement in weak-signal reception, the system was widely deployed.
Short-range agent communications, known as SRAC systems, represented a technological revolution for covcom when OTS deployed the first units to agents inside the Soviet Union in the mid-1970s. SRAC enabled the agent and case officer to exchange information without being required to come into close proximity, or conduct a clandestine act such as loading a drop that might be observed. It also eliminated the risk of leaving sensitive material unattended in a dead drop, which might be discovered and traced back to the agent.
The original SRAC systems exchanged short-duration, encrypted radio-frequency messages of a few hundred characters in less than five seconds between two black-box transceivers. An agent carried a pocket-sized SRAC unit in his coat and “shot” his message at designated locations at any time, day or night. He did not need to know, or be concerned about, the location of the SRAC receiver, which could have been located in an embassy, a residence, or in the handbag of a lady standing in front of a department store. SRAC defeated physical surveillance by eliminating the requirement for agent and case officer ever to be in the same location. It was, however, potentially vulnerable to signal interception if an opposition service was monitoring the SRAC frequency at the time and in the area of a transmission.
Because SRAC could be initiated by the agent, the CIA then had a reliable capability to receive time-sensitive reporting and could immediately retask the agent with follow-up requirements.46 When military tensions between Greece and Turkey were at the flash point during the 1990s, senior CIA officers credited the near-real-time agent reporting through SRAC systems with preventing war between the two countries. SRAC was the principal covcom link between the CIA and General Dimitri Polyakov when the latter actively spied for the United States during the 1970s in Moscow, and later played a critical role in Colonel Kuklinski’s successful 1980 exfiltration from Poland.
The SRAC device used by Kuklinski was prepared for him under an OTS project code-named DISCUS and was known at the Warsaw station under the code name ISKRA.47 It was described as follows:
The size of a pack of cigarettes, it weighed about half a pound and had a keyboard and memory. Kuklinski could type in a message at home, place the device in his pocket, and carry it somewhere else. There he could push the transmission button without removing the ISKRA from his pocket. The device had a small window through which a single line of text could be read, from an outgoing or incoming message. If he transmitted directly into the embassy, an alarm would sound in the Warsaw station. As a rule, Kuklinski was asked to leave a signal in the morning that he would transmit in the night, and an officer would take another ISKRA outside to receive the message.48
The OTS SRAC systems were an early form of text messaging. In the 1980s, receive-only digital pagers were introduced to the consumer market, and later enhanced in the 1990s with the capability to both transmit and receive messages. Once text messaging over cell phones was developed, the use exploded globally, with hundreds of millions of messages being sent daily. Both pagers and cell phones offered new potential for covcom and possessed added advantage that the agent did not require dedicated spy gear to communicate. However, these systems were particularly vulnerable to counterintelligence detection if not operated with the disciplined tradecraft needed to maintain their clandestine use.
As early as the mid-1960s, the CIA recognized the potential for using satellites for agent communications. The idea was that an agent with a small handset could beam his information to an orbiting satellite, which, in turn, would relay the data to a receiving site. By combining a satellite-send system with his OWVL, the agent could transmit and receive secret intelligence inside his home country without personal contact with a CIA officer. The capability, first deployed in the late 1960s under the codename BIRDBOOK, used low-earth-orbit satellites as “bent-pipe” relays for the agents’ messages.49
Unfortunately, field realities limited the operational use of BIRDBOOK. Agents had only a five-to-seven-minute window to “shoot” the message to the satellite as it arced across the sky. Success also depended on a clear line-of-sight transmission path as well as the precise orientation and positioning of the transmit antenna. 50 Hostile counterintelligence services learned of the system and developed means to intercept the signal and triangulate the agent’s position using direction-finding techniques.
Despite its limitations, BIRDBOOK demonstrated that satellites, signal processing, and component technology could be integrated into a long-range covcom system. Over the next two decades, new generations of government and commercial satellites increased global coverage and signal processing improvements made lower power transmissions possible. Advances in electronic components, combined with an understanding of the tradecraft necessary for securely operating a satellite transmitter, addressed many of the problems at the agent’s end of satellite covcom. A decade before satellite phones were available, OTS, with its industry and government partners, had created a similar covert capability for a small number of highly select CIA agents.
While appearing simple in concept, covcom systems, including the most sophisticated and technically advanced, are difficult to design and exacting in their use if they are to be employed successfully. Each technological advance, from the telegraph to the Internet, added another means of communication, but technical officers had to devise means of assuring security and covertness before the technology could be used in clandestine operations. In the end, whether the secret message is written in the disappearing ink of Caesar’s day or encoded in a radio-frequency signal transmitted by satellite, covert communication between agent and handler relies on both the technique used and confidence that the exchange cannot be detected or read by anyone except the intended parties. However, as the final decade of the twentieth century unfolded, covcom, like the other pillars of tradecraft, would be revolutionized by the electronic tidal wave of digital technology, steganography, and the Internet.
