Talk:Double-Cross system

To do. Please write a brief definition or description of this article at Double-Cross system/Definition.

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Hi, Howard. I think you're using *way* too many initials here. You gotta remember that the average reader doesn't have a clue as to what HUMINT, IMINT, and SIGINT mean. And the first mention of WWII should be spelled out.... Best, Hayford Peirce 16:54, 5 June 2008 (CDT)

OK, will expand and link.

As far as "all" German spies, I tend to believe it, for several reasons. First, no one has ever surfaced with a credible story of being an uncaught spy. Second, nothing in captured records or debriefings indicated the Germans were getting any HUMINT that didn't come from a controlled source. Third, the Abwehr (military intelligence, before it was broken up due to involvement in anti-Hitler activities) was running the spies, and that their message traffic was in an Enigma version that was being read. Fourth (a little softer) the Germans bought the Plan Bodyguard strategic deception that Double-Cross supported; before Normandy, all German eyes were on the Pas de Calais, which was the fake invasion. While the local generals concluded Normandy was the real thing, Hitler still wouldn't believe it wasn't a feint and the real major invasion was yet to come.

Somewhat supporting was that a certain number of German high-altitude reconnaissance planes were allowed to get back to Germany, and the main reconnaissance effort came exactly where Bodyguard wanted the Germans to believe the (mythical) First United States Army Group (FUSAG), under Patton, was staging. Howard C. Berkowitz 17:24, 5 June 2008 (CDT)

Thanks, Hayford. Should I have mentioned RUMINT and ININT, or Rumor Intelligence & Initial Intelligence? Seriously, there get to be some fairly exotic tradecraft techniques to signal if one is under enemy control, and for a competent counterespionage organization to prevent such warnings.

Good note; good example of talk page vs. article collaboration. While there are some British records that may not declassify until 75 years after 1945, or the death of the last participant, I'd really be surprised if anything surfaced at this point. It's indirect evidence, but another confirmation is that the Nazis seemed to accept all of their doubled agent reports, and not take actions inconsistent with them.

The agents, by and large, were not especially ideological; at least the ones who were doubled. XX gave them the choice "double or die", and some, indeed, preferred the rope. Howard C. Berkowitz 13:12, 6 June 2008 (CDT)

I think you should put in anything you think should be there as long as we don't drown in a sea of acronyms or whatever they're called. I used to love reading the Tommy Hambledon novels by Manning Coles -- some of the wartime ones were particularly good, although a couple were deadly dull. Both of the writers were involved with War Office Intelligence one way or another -- I wonder what they would have written (after the war) if they had been aware of Enimga etc.? Hayford Peirce 14:08, 6 June 2008 (CDT)

There are two techniques, one arguably counter-counterintelligence and the other counter-counter-counterintelligence, or maybe the other way around. The first is generally called a "bluff check", and is a way for an double agent to warn his own side that he is under control. There tended to be a specific check for each agent, but it might be something such as spelling correctly a word he routinely misspelled, or perhaps putting an extra letter into the second word of the third sentence, or just using some unremarkable word that he is careful never to use in regular messages.

The second method, which had a specific British tradecraft name that I'm trying to remember, was analogous to speaker-dependent voice recognition, but for Morse code telegraphy rather than speech. I'm almost illiterate in Morse, but apparently, each operator has characteristic patterns -- the length of a dot, the length of a dash, the delay between them in a character, the delay between words, etc. An experienced receiving operator can simply listen and sense, at the least, "Adolf sounds odd today".

Today, that sort of thing is a branch of radiofrequency measurement and signature intelligence (MASINT), a relatively recent name for something that has been around at least since WWII. For example, the Japanese fleet sailing to Pearl Harbor made a point to leave all its regular radio operators at home, so their transmissions, which direction finding would place in the Inland Sea, would have the right fist.

The British, IIRC, found that female operators tended to have a better ear for changes in fist, but, to reduce the skill needed, they'd sometimes record the Morse transmission onto an oscillograph -- the storage oscilloscopes of the time, using photographic film or even a pen recorder -- to store some of the Morse transmission. If a known signal was on a transparency, it could be overlaid onto a more recent transmission, and variations literally seen. There was a WWII code word for this, and I can't quite come up with it from memory. It'll probably come to me just as I'm about to fall asleep. Howard C. Berkowitz 15:00, 6 June 2008 (CDT)