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On which text editor is it easiest to prevent and/or eliminate watermarking?

Pre-installed malware that defeats anonymity being used on an airgapped system can be made ineffective, at least partially, by making sure the device does not have any of the hardware necessary to connect to the internet.

But what about watermarking? One would have to eliminate the metacontent of any traffic you want to send in a text file, and then look at it closely in hex editor.

Is there an easier way to make sure that a file has not been watermarked? On which text editor is this easiest?

Patriot
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  • What kind of watermarking malware and how does it operate? Knowing more about the malware and how it operates might help get a better answer for you. – hft Jun 28 '19 at 22:54
  • That makes sense. This question focuses on pre-installed malware, probably the kind that nobody knows about yet. I agree with you entirely, but I was still hoping for an answer that takes the viewpoint of a particular text editor against all possible watermarks. – Patriot Jun 29 '19 at 01:50

2 Answers2

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On which text editor is it easiest to prevent and/or eliminate watermarking?

It's impossible, or nearly so, unless you know the correct text. Watermarking is in general a mark that can be used to distinguish a single copy afterwards. This may be as simple as having two spaces in a text; edit this answer and you will see that.

Other ways may be replacing some words. For instance, I can replace "I had pasta for lunch today" with "I had fish for lunch today", and without knowing if the text exists in other forms, you have no way of telling. To me, as author, it would be trivial to pinpoint whom had leaked, if every recipient got a unique text, yet impossible for any one recipient to discover it, without talking to other recipients.

Another good alternative would be to somehow misspell a word here and there. This may look accidential to the receiver...

That said. If you want to exchange text, exchange text. Not word files or any other obscure, possibly binary format. Heck, word files can even include active content such as Visual Basic Macros!

If formatting is desired, I'd suggest some open, verifiable formatting, such as markdown or HTML.

vidarlo
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It depends on the type of watermarking.

For example, suppose someone inserted some non-printable characters into a string to watermark it.

E.g., User0's text file contains:

"r\x00a\x00t\x00s"

Which, when printed to terminal with the cat command shows:

rats

E.g., User1's text file contains:

"r\x00a\x00t\x01s"

Which, when printed to terminal with the cat command shows:

rats

Indistinguishable.

But if I open User0's file in VIM, I see:

r^@a^@t^@s

Whereas if I open User1's file in VIM, I see:

r^@a^@t^As

Which is distinguishable.

Of course, I could also do this with a hex viewer like xxd, but VIM is a text editor that works too.

hft
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