Spycraft - Melton [248]
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