Is it possible to reveal that a file was downloaded over Tor?

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8

  1. Is marking a file as downloaded over Tor possible without Javascript?
    Yes. The site examines the IP. It is Tor. Mark the file the user wants to download.

  2. Is there a way of sanitizing a file from marks such as “the file was downloaded over Tor,” in a way like Dangerzone or so?
    I only heard of Dangerzone just now. Interesting. The mark(s) could be very simple and devious. I will use the word copyright as an example since most files/programs would contain this. The mark is changing copyright to Copyright or vice versa. It is a 1 bit change. Same idea for a zip.
    0100 0011 to 0110 0011

Would Dangerzone catch this? A CRC would but then you cannot do it via clearnet.

  1. Do you have any other ideas to ultimately have a file that certainly has no marks it was downloaded over Tor?
    I do not as explained in 2.

OK, even in this restrictive environment someone must know someone in a “free” environment to get a clearnet copy and compare CRCs. But wait, the word Stasi (DDR) comes to mine where 1 in 4 people were informants and that someone in a “free” environment could be a sleeper or plant. (Bill Haydon in Tinker Tailor Soldier Spy)

Sorry I can’t answer this question. Nothing is 100% if on the internet.