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A case study in PDF forensics: The Epstein PDFs

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Re: A case study in PDF forensics: The Epstein PDFs

#111

Post by tombrossman »

streetfighter64 wrote: post #102
tombrossman wrote: post #90

Earlier quoted context omitted.

GNOME Desktop users can put this in a Bash script in ~/.local/share/nautilus/ for more convincing looking fake PDF scans, accessible from your right-click menu. I do not recall where I copied it from originally to give credit so thanks, random internet person (probably on Stack Exchange). It works perfectly. ROTATION=$(shuf -n 1 -e '-' '')$(shuf -n 1 -e $(seq 0.05 .5)) for pdf in "$@"; do magick -density 150 $pdf \ -…

Shouldn't $ROTATION be set inside the loop and actually used in the magick command?

You know, now that you point it out that seems obvious. I think maybe I was experimenting with rotation and left that in, unused. I did this years ago. The loop works OK though. Thanks for the feedback (and now I have to finish editing that script ...)

Re: A case study in PDF forensics: The Epstein PDFs

#112

Post by GaryBluto »

WetMinister wrote: post #82
GaryBluto wrote: post #42

Earlier quoted context omitted.

/pol/ in no way started the American culture war. It was brewing for a while.

You’re acting as if https://doge.gov does not exist. Ask yourself under which presidency, administration and kind of politics such is allowed to even exist with a straight face.

It would've existed regardless of internet memes, just under a different and similarly obnoxious name.

Re: A case study in PDF forensics: The Epstein PDFs

#113

Post by mort96 »

ronnier wrote: post #94
mort96 wrote: post #62

Earlier quoted context omitted.

Just to substantiate this a bit: I remember a gleeful consensus in certain circles being that /pol/ and /r/the_donald had "memed Trump into the White House". It's much more complicated than that, but there's certainly an element of truth there.

Then Reddit and almost all of social media went on to purge trump and pro trump content. The Donald was banned. Trump deplatformed across social media.

That's true, but not really relevant to this discussion. You can't really deplatform a president; yes he was no longer on Twitter, but roughly 8 billion people listen any time he speaks.

Re: A case study in PDF forensics: The Epstein PDFs

#114

Post by Exoristos »

ge96 wrote: post #103
zxcvasd wrote: post #72

Earlier quoted context omitted.

this is a well-studied field (stylometry). when combining writing styles, vocabulary, posting times, etc. you absolutely can narrow it down to specific people. even when people deliberately try to feign some aspects (e.g. switching writing styles for different pseudonyms), they will almost always slip up and revert to their most comfortable style over time. which is great, because if they aren't also regularly changi…

People do change over time, I used to write "ha" after every sentence for some reason

You left off something.

Re: A case study in PDF forensics: The Epstein PDFs

#115

Post by barrkel »

tombrossman wrote: post #90
anigbrowl wrote: post #71

I found this part interesting: There are also other documents that appear to simulate a scanned document but completely lack the “real-world noise” expected with physical paper-based workflows. The much crisper images appear almost perfect without random artifacts or background noise, and with the exact same amount of image skew across multiple pages. Thanks to the borders around each page of text, page skew can easi…

GNOME Desktop users can put this in a Bash script in ~/.local/share/nautilus/ for more convincing looking fake PDF scans, accessible from your right-click menu. I do not recall where I copied it from originally to give credit so thanks, random internet person (probably on Stack Exchange). It works perfectly. ROTATION=$(shuf -n 1 -e '-' '')$(shuf -n 1 -e $(seq 0.05 .5)) for pdf in "$@"; do magick -density 150 $pdf \ -…

That seq is probably supposed to be $(seq 0.05 0.05 0.5). Right now it's always 0.05.

Note that you can get random numbers straight from bash with $RANDOM. It's 15 bit (0 to 32767) but good enough here; this would get between 0.05 and 0.5: $(printf "0.%.4d\n" $((500 + RANDOM % 4501)))

Re: A case study in PDF forensics: The Epstein PDFs

#116

Post by toast0 »

mmooss wrote: post #105
toast0 wrote: post #54

Earlier quoted context omitted.

> What is the legal basis for releasing the someone's private files and communications? An act of congress, for one. Also, AFAIK, federal privacy generally ends at death, as does criminal liability; so releasing government files from a federal investigation after death of the subject is generally within the realm of acceptable conduct.

Yes, I forgot about that major part of the story! Still, acts of Congress can't violate Consitutional rights. It seems unlikely you lose all rights when you die or it would be chaos - imagine all the secrets people die with that affect everyone they know. An integral part of every estate plan would be incinerating records. Wills do have real power.

Your estate retains many of your rights when you die. However, the federal privacy act explicitly does not apply. Your estate may have privacy rights via the Constitution, although privacy is not specifically enumerated. Your estate may have privacy rights via state law; but that wouldn't bar the federal government from disclosing its investigative materials.

OTOH, there's a 2004 case, National Archives & Records Administration v. Favish[1], which establishes the surviving family's right of privacy to death scene photos, but that's technically not privacy of the deceased.

[1] https://www.justice.gov/archives/oip/blog/foia-post-2004-sup...

Re: A case study in PDF forensics: The Epstein PDFs

#117

Post by zxcvasd »

ge96 wrote: post #103
zxcvasd wrote: post #72

Earlier quoted context omitted.

this is a well-studied field (stylometry). when combining writing styles, vocabulary, posting times, etc. you absolutely can narrow it down to specific people. even when people deliberately try to feign some aspects (e.g. switching writing styles for different pseudonyms), they will almost always slip up and revert to their most comfortable style over time. which is great, because if they aren't also regularly changi…

People do change over time, I used to write "ha" after every sentence for some reason

sure, not denying that. my writing style is fairly different now in my 40s than it was in my late teens/early twenties.

but, those changes are usually pretty gradual and relatively small. thats why when attempting to identify someone via writing, you look at several aspects of the writing and not just word choice (grammar, use of specific slang, sentence length, paragraph structure, punctuation, etc.). it is highly unlikely that all aspects of someones writing changes at the same time. simply removing "ha" is inconsequential to identification if not much else changed.

additionally, this data is typically combined with other data/patterns (posting times, username (themes, length, etc.), writing that displays certain types of expertise, and more) to increase the confidence level of correct identification.

Re: A case study in PDF forensics: The Epstein PDFs

#118

Post by ThePowerOfFuet »

agopo wrote: post #99
juujian wrote: post #87

Earlier quoted context omitted.

Not that I can speak from personal experience or anything... But somebody on an email chain may have requested a scanned version of the document to ensure there is no metadata and the employee might have found it easier to just flatten the pdf and apply a graphical filter to make the document appear like a scanned document. There might even be a webtool available somewhere to do so, I wouldn't know...

[dead]

Straight to the signup page? A bit blatant, no?

Re: A case study in PDF forensics: The Epstein PDFs

#119

Post by wholinator2 »

ge96 wrote: post #103
zxcvasd wrote: post #72

Earlier quoted context omitted.

this is a well-studied field (stylometry). when combining writing styles, vocabulary, posting times, etc. you absolutely can narrow it down to specific people. even when people deliberately try to feign some aspects (e.g. switching writing styles for different pseudonyms), they will almost always slip up and revert to their most comfortable style over time. which is great, because if they aren't also regularly changi…

People do change over time, I used to write "ha" after every sentence for some reason

You know, i had a particularly cringy period in which i put "la" at the end of sentences.

Re: A case study in PDF forensics: The Epstein PDFs

#120

Post by hiccuphippo »

anigbrowl wrote: post #71

I found this part interesting: There are also other documents that appear to simulate a scanned document but completely lack the “real-world noise” expected with physical paper-based workflows. The much crisper images appear almost perfect without random artifacts or background noise, and with the exact same amount of image skew across multiple pages. Thanks to the borders around each page of text, page skew can easi…

I mean, I do that all the time when they ask me to print something, sign it, and then scan it.

Sign a blank paper, scan it, paste the original doc on it. Then keep the scan for future docs.

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