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Back in the Usenet days, around the late '80s, I had read somewhere/somehow a few years before about how classified information would be printed with tiny diffe
by tacon 9y ago
Back in the Usenet days, around the late '80s, I had read somewhere/somehow a few years before about how classified information would be printed with tiny differences in spacing to track leaks to foreign adversaries. In some newsgroup, I happened to mention I had read about this technique, which while obvious once you think of it was apparently not well known. Certainly by that time, it was very well known to the KGB.
Months after my public comment, I got a phone call from an AT&T inventor who was prosecuting a patent on the same technology. They were very interested where I had read about the technique in the public literature. Alas, I could not remember where I had read that little factoid so I wasn't much use to them. It was disturbing to them that their patent claim was out in the open literature somewhere, but they could not find it.
- dsr_ 9y agoWhitespace chars at the end of lines was used to encode formatting information; I think clari.net news services were the primary users.
- TrainedMonkey 9y agoSome printers do that, it is very expensive and mostly moot because of electronic documents. See https://qz.com/1002927/computer-printers-have-been-quietly-embedding-tracking-codes-in-documents-for-decades/ https://qz.com/1002927/computer-printers-have-been-quietly-e...
- gruez 9y agoparent was discussing about tiny differences in word/letter spacing, not invisible dots.
- QAPereo 9y agoThe general idea is called a Canary Trap, and IIRC it was popularized by Tom Clancy. The most common form is to have some subtle variations in the content or wording, which would give away the origin. Edit here we go https://en.m.wikipedia.org/wiki/Canary_trap https://en.m.wikipedia.org/wiki/Canary_trap The Canary Trap, aka The Barium Meal.
- tclancy 9y agoThanks for the credit, but I work exclusively in longhand. [note the extra space please]
- kbenson 9y agoI spent far too long looking at your comment history trying to figure out if you really were the author (since others have shown up here) until I stumbled on something semi-verifiable and visited Wikipedia (which should have been my first stop), only to learn the author Tom Clancy passed away a few years ago. :)
- tclancy 9y agoYou would be shocked to learn how many Twitter users don't bother doing either before writing to me.
- lojack 9y agoOne of the alliances in Eve online used to do this type of counter intelligence to assist in identifying spies releasing internal communications. They’d also introduce invisible watermarks in any images they posted. My understanding was their leadership had a tool to help them select a few synonyms in anything they wrote, and a few synonyms was all it took to identify the account releasing the communication.
- abstractbeliefs 9y agoMore than one. PL, Goons, Test, various Russian alliances, and some smaller players all would. I really loved EvEs (counter)intelligence scene, it felt like a great place to safely dabble in real tools and techniques like this.
- kpU8efre7r 9y agoIsn't that mentioned in The Cardinal of the Kremlin?
- NickNameNick 9y agoI think they mention it as being ineffective. The method mentioned in the book involves inserting inflammatory quotes into different versions of a report, in the hopes that the quote will show up somewhere.
- jgalt212 9y agoIt is. https://books.google.com/books?id=Vj-NDQAAQBAJ&pg=PA346&dq=canary+intitle:cardinal+intitle:of+intitle:the+intitle:kremlin&hl=en&sa=X&ved=0ahUKEwjkxZHjhbjYAhWCY98KHepwADMQ6AEIKTAA#v=onepage&q=canary%20intitle%3Acardinal%20intitle%3Aof%20intitle%3Athe%20intitle%3Akremlin&f=false https://books.google.com/books?id=Vj-NDQAAQBAJ&pg=PA346&dq=c... Red Sparrow also has a canary trap, and they refer to it thusly. https://books.google.com/books?id=l-lnAwAAQBAJ&pg=PA428&dq=canary-trap+intitle:red+intitle:sparrow&hl=en&sa=X&ved=0ahUKEwiSiY2IhrjYAhUhleAKHa63CgUQ6AEIKTAA#v=onepage&q=canary-trap%20intitle%3Ared%20intitle%3Asparrow&f=false https://books.google.com/books?id=l-lnAwAAQBAJ&pg=PA428&dq=c...