Barium Meal Test
According to the book Spycatcher by Peter Wright (published in 1987) the technique is standard practice that has been used by MI5 (and other intelligence agencies) for many years, under the name "Barium meal test". A Barium meal test is more sophisticated than a canary trap because it is flexible and may take many different forms. However, the basic premise is to reveal a secret to a suspected enemy (but nobody else) then monitor whether there is evidence of the fake information being utilised by the other side. For example, the double agent could be offered some tempting "bait" e.g. be told that important information was stored at a dead drop site. The fake dead drop site could then be periodically checked for signs of disturbance. If the site showed signs of being disturbed (in order to copy the microfilm stored there) then this would confirm that the suspected enemy really was an enemy e.g. a double agent.
Read more about this topic: Canary Trap
Famous quotes containing the words meal and/or test:
“Bid a strong ghost stand at the head
That my Michael may sleep sound,
Nor cry, not turn in the bed
Till his morning meal come round;
And may departing twilight keep
All dread afar till morning’s back....”
—William Butler Yeats (1865–1939)
“The test of an adventure is that when you’re in the middle of it, you say to yourself, “Oh, now I’ve got myself into an awful mess; I wish I were sitting quietly at home.” And the sign that something’s wrong with you is when you sit quietly at home wishing you were out having lots of adventure.”
—Thornton Wilder (1897–1975)