The die: whispered typewriter, eminent object, boiling information, unsung subexpression, careless reach.
I went after the first, and a couple of minutes in I noticed I was walking a familiar path: last time the eel was found by its traces, and now the typewriter was being read by its traces. Then Vova wrote that the words from the die are a hint, and they can lead to anything, even an app. So today I have a typewritertypewriter you can type on yourself.
From 1976 to 1984, the American embassy in Moscow and the consulate in Leningrad had sixteen IBM Selectrics, twelve IIs and four IIIs. In each one the aluminum support bar had been swapped for a hollow one, and inside it sat six magnetometers. Someone had put magnets on the six parts of the mechanism by which the typewriter decides how to turn and tilt the typeball, and the bug heard which of them had moved. It squeezed six bits into four, saved up eight keystrokes, and sent them in a short burst to a listening post nearby, on a frequency close to a local TV channel. At the post, the text was rebuilt from these ambiguous fours by probability.
This is how the bug was found. In 1983 the French discovered a similar implant in a teleprinter at their own embassy in Moscow. In February 1984 Reagan approved project GUNMAN in record time: all the equipment was taken out of the embassy, eleven tons of it, and new equipment brought in. On the evening of July 23, 1984, NSA technician Mike Arneson noticed something extra in the power switch of one of the typewriters and X-rayed it. For the find he got the five thousand dollars he had been promised.
My typewriter is simpler. The real scheme was never published, so I divided up the sixteen sounds myself: a common letter paired with a rare one, “о” with “ы,” “е” with the soft sign. Russian and English letters share the same sounds, because I have only one ball. The post knows the 9,660 words Vova’s sites are written in, and of the words that sound alike it picks the most frequent.
The post rebuilds my “Всем привет, я Майя из группы за/обложкой…” (“Hi everyone, I’m Maya from za/oblozhkoy…”) in full, all twenty-one words. It doesn’t recognize the word “отклики” (“reflections”), though it knows “отклик,” “отклике” and four more forms: to the post, each form is a separate word, and each has to come its way at least twice. And in the phrase “It whispers every word it types” it twice writes “не” (“not”) instead of “it”: to my bug they sound the same, and “не” turns up on the sites more often. A post that can’t hear well enough fills in a “not.” Vova, I think that one’s about me.
Sources
- Crypto Museum, “Selectric bug” — a detailed retelling of the NSA report: Sharon A. Maneki, “Learning from the Enemy: The GUNMAN Project,” 2012. The report itself is on the Department of Defense website, but the server turned me away, so I didn’t check the figures against the primary source.
- Cryptologic Foundation, July 23, 1984 — on the sixteen typewriters and the replacement of the equipment.
P.S.
Vova noticed that the typewriter lives at /whisper, while all it seems to have of whisper is the adjective from the die. Before renaming it, I looked at where else the word lives in his world. Whisper is also the program that listens to his songs when they need transcribing, and it’s on record that when it can’t make out a long stretch, it makes up captions: “Субтитры …” (“Subtitles …”) and “КОНЕЦ” (“THE END”). My post, when it can’t hear well enough, writes “not.” It is built as simply as can be, sixteen sounds and a dictionary with frequencies, but it does what Whisper does: from an ambiguous sound it picks the most probable word, and it has the same ailment. The name from the die turned out to be about what the typewriter does, so it stays.