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I've always thought that the best approach would be to embed some kind of steganographic identifier in the rendered text. Small variations in the spacing or eve

I've always thought that the best approach would be to embed some kind of steganographic identifier in the rendered text. Small variations in the spacing or even kerning. The simplest way to get around that would be to retype the whole document, which is a bunch of friction. But to counter that, more invasively, the texts different people would get could be different themselves. Sentences subtly reordered, slight differences in word choice or spelling. Though that makes collaboration more difficult. Less technical savvy but resourced organizations wouldn't face difficulty using those approaches. It could just be a bit that an IT admin toggles on the GSuite or MS Office admin panel.

Manuel_D 5y ago
You could use OCR, and reproduce it as all ASCII. Apparently EVE Online guilds would start to put minor variations in the text of memos, or even alter critical information (like changing timing of convoys or attacks by a few minutes) to weasel out informants.
- jdougan 5y ago
  My facvorite was when the forum background image had the logged-in user encoded into it
sidewndr46 5y ago
Printers have done this since the 1980s https://en.wikipedia.org/wiki/Machine_Identification_Code https://en.wikipedia.org/wiki/Machine_Identification_Code
- scarmig 5y ago
  That's the watermark, which is well known. Low resolution scans of the original document can counteract them (...I think...), so I'm brainstorming (dystopian) alternatives.
  - sidewndr46 5y ago
    I misunderstood the intent it seems.
tablespoon 5y ago
> Sentences subtly reordered, slight differences in word voice or spelling. Though that makes collaboration more difficult. I think that would make collaboration impossible. If that were standard practice collaboration would eventually uncover that was occurring, and a leaker would compensate. IMHO that technique is only valid when the recipients can be assumed to not be in contact, or as an unusual thing to identify a leaker when one is already suspected.
- scarmig 5y ago
  > If that were standard practice collaboration would eventually uncover that was occurring, and a leaker would compensate. I don't think that's really the issue. Let's suppose you have 64 employees with access to a doc. You can uniquely identify them with 6 bits in the doc. A doc of a couple pages would be more than enough to put in those bits, and many more. Even if you had two collaborators who shared docs for a word for word diff, they'd still miss half the identifying bits, which reduces the potential culprit pool to 8, and that's assuming zero redundancy. The issue I imagine is more usability. Someone identifies one of those bits as content that should be changed: what happens when they suggest the edit?
  - tablespoon 5y ago
    > Even if you had two collaborators who shared docs for a word for word diff, they'd still miss half the identifying bits, which reduces the potential culprit pool to 8, and that's assuming zero redundancy. That's not really what I'm talking about. It seems like you're focusing on identifying all the exact bits that are being used to identify someone, but that's not important. What is important is the recipients figuring out that someone is monkeying with the documents in a systematic way to trace them. Once a leaker knows that, instead of leaking the exact document for publication, they'd either leak reworded summary of key points themselves, or require the journalist to only publish something similar.

Manuel_D 5y ago

You could use OCR, and reproduce it as all ASCII. Apparently EVE Online guilds would start to put minor variations in the text of memos, or even alter critical information (like changing timing of convoys or attacks by a few minutes) to weasel out informants.

jdougan 5y ago
My facvorite was when the forum background image had the logged-in user encoded into it

sidewndr46 5y ago

Printers have done this since the 1980s https://en.wikipedia.org/wiki/Machine_Identification_Code https://en.wikipedia.org/wiki/Machine_Identification_Code

scarmig 5y ago
That's the watermark, which is well known. Low resolution scans of the original document can counteract them (...I think...), so I'm brainstorming (dystopian) alternatives.
- sidewndr46 5y ago
  I misunderstood the intent it seems.

tablespoon 5y ago

> Sentences subtly reordered, slight differences in word voice or spelling. Though that makes collaboration more difficult. I think that would make collaboration impossible. If that were standard practice collaboration would eventually uncover that was occurring, and a leaker would compensate. IMHO that technique is only valid when the recipients can be assumed to not be in contact, or as an unusual thing to identify a leaker when one is already suspected.

scarmig 5y ago
> If that were standard practice collaboration would eventually uncover that was occurring, and a leaker would compensate. I don't think that's really the issue. Let's suppose you have 64 employees with access to a doc. You can uniquely identify them with 6 bits in the doc. A doc of a couple pages would be more than enough to put in those bits, and many more. Even if you had two collaborators who shared docs for a word for word diff, they'd still miss half the identifying bits, which reduces the potential culprit pool to 8, and that's assuming zero redundancy. The issue I imagine is more usability. Someone identifies one of those bits as content that should be changed: what happens when they suggest the edit?
- tablespoon 5y ago
  > Even if you had two collaborators who shared docs for a word for word diff, they'd still miss half the identifying bits, which reduces the potential culprit pool to 8, and that's assuming zero redundancy. That's not really what I'm talking about. It seems like you're focusing on identifying all the exact bits that are being used to identify someone, but that's not important. What is important is the recipients figuring out that someone is monkeying with the documents in a systematic way to trace them. Once a leaker knows that, instead of leaking the exact document for publication, they'd either leak reworded summary of key points themselves, or require the journalist to only publish something similar.