Hacker News

Top stories

Live mirror
30 storiesupdated just nowView source snapshot
  1. MiMo v2.6(xiaomi.com)
    357comments
  2. Spymarks, Not Watermarks(brand.io)
    76comments
  3. Apple Music to open concert venue in Battersea Power Station(bbc.com)
    25comments
  4. Transformers Explained Visually(poloclub.github.io)
    53comments
  5. Attention is all you have(alicegg.tech)
    214comments
  6. What Sun got wrong(dtrace.org)
    324comments
  7. I don't want to read what you didn't write(colinbreck.com)
    204comments
  8. MiMo-v2.6-Pro: Intelligence, Performance and Price Analysis(artificialanalysis.ai)
    4comments
  9. NASA’s Mars Sample Return mission is dead(science.org)
    306comments
  10. AI coding has made CI a bottleneck, so we reworked ours to keep up(linear.app)
    218comments
  11. Looking forward to Git 2.56 – and 3.0(lwn.net)
    41comments
  12. Can gzip be a language model?(nathan.rs)
    discuss
  13. Divide by depth for instant 3D(gabrieloc.com)
    23comments
  14. The Advisory Group on Mathematics and Artificial Intelligence(terrytao.wordpress.com)
    58comments
  15. World Wide Words(worldwidewords.org)
    discuss
  16. Socrates vs. the Written Word (2011)(wondermark.com)
    11comments
  17. Claude Status – Elevated errors for multiple models(claude.com)
    72comments
  18. PDF Forgeries Are Surprisingly Rare (2022)(gwern.net)
    22comments
  19. How do traffic signals work? (2019)(practical.engineering)
    53comments
  20. First Shader from Zero in Godot 4(gdquest.com)
    6comments
  21. Python Workers are now generally available(cloudflare.com)
    36comments
  22. Frontier AI on Your Own Hardware(timdettmers.com)
    75comments
  23. Paper Models of Polyhedra(polyhedra.net)
    discuss
  24. Grok 4.7(x.ai)
    468comments
  25. Turn off and restrict access to Apple Intelligence features on Mac(support.apple.com)
    191comments
  26. HERMES radio enables voice and data communication over vast distances(ieee.org)
    53comments
  27. Apple Copland D11E4 Booting in the Browser(pagetable.com)
    37comments
  28. More floating point alternatives(wizardzines.com)
    18comments
  29. Why does mathmain need an encrypted loader?(safedep.io)
    37comments
  30. Used ThinkPad Buyer's Guide (2019)(bobble.tech)
    discuss

PDF Forgeries Are Surprisingly Rare (2022)

26 pointsby 1d agogwern.net
23 comments
3h agoHN ↗

PDF forgery is striking because it’d be so easy to do: find a useful research paper, edit it in any of the many PDF utilities, upload anywhere, wait for people to copy it (as they do), then take down yours; now you have an authoritative peer-reviewed research paper floating around the Internet with no links to you, in the perfect crime. (Or better yet: upload it directly to Libgen/Sci-Hub and let everyone else redistribute it.)

Seen as (unsigned) PDFs are basically images of documents, it's wild to claim that there are no forgeries, anyone doing a good ole fake document, fake diploma, fake wire transfer, fake articles of incorporation, etc... is using a pdf for faking. A nigerian prince scam sending an attachment mentioning 15.000.000$ locked up in inheritance would constitute a PDF forgery.

2h agoHN ↗

Gwern is talk about editing an existing pdf. Less so about creating one from scratch.

There is plenty of incompetence, fraud, and malice online, often in PDFs… but only new PDFs. I can’t think of a single fraud accomplished by editing a real PDF & just uploading it for Google Scholar etc. or where I’ve been burned by even mislabeling.

2h agoHN ↗

I believe it's actually linked in the OP about half way down. What a crazy thing for an agent to do - to turn a minor disagreement into a maybe-crime.

2h agoHN ↗

Gwern, in case you are reading this, there's a typo in:

(In the rare cases anyone tampers with PDFs, it quickly turns into a technical morass and he-said-she-said, and requires several orders of magnitude more effort to prove than to do; consider the hoops epxperts had to jump through in the Craig Wright cases, or even just a landlord editing a contract—where the contract was done through a digital document timestamping service!)

Specifically "epxperts"

2h agoHN ↗

Offtopic but the damage caused to an entire generation by Gwern's nicotine article is truly astounding. Obviously he's not responsible for the actions of others and it was written with good intentions but wow.

2h agoHN ↗

I have no sense of gwen's readership numbers, but I find it unlikely that one rather erudite blog has anything to do with global nicotine consumption. People have been smoking for centuries. The vaping industry had guerilla marketing campaigns to target college kids.

No rain drop thinks it is responsible for the flood, but I am hard-pressed to imagine a blog article greatly swayed hearts and minds.

1h agoHN ↗

Yeah, once you remove the hazards inherent in cigarette and/or cigar smoking from the discussion, the only solid objection I've heard to nictotine consumption is that it's probably more addictive than caffeine.

I understand why personal vaporizer use was demonized, but -goddamn- that's going to be a public health disaster only an order of magnitude or two smaller than when folks started demonizing nuclear power back in the mid 1900's.

31m agoHN ↗

the only solid objection I've heard to nictotine consumption is that it's probably more addictive than caffeine.

s/probably/massively. You don't see ads and public health messages for quitting coffee, you don't see bans for coffee advertising, but you do see a whole lot of things aimed at reducing or quitting nicotine products.

Besides, nicotine withdrawal is utter hell. Caffeine withdrawal usually is solved by a night of good healthy sleep - most people drink coffee (or energy drinks) only because they are forced by circumstances to work against their chronotype.

4m agoHN ↗

You don't see ads and public health messages for quitting coffee, you don't see bans for coffee advertising,

You would if coffee has the same probability of causing cancer as smoking.

Being addictive on its own is rarely a reason to demonise a substance. The addictive substances that are demonised are always those that also have negative health effects, even in moderation (like smoking).

1m agoHN ↗

You don't see ads and public health messages for quitting coffee, you don't see bans for coffee advertising...

That'd be because -unlike cigarette and cigar smoking- coffee doesn't create a substantially elevated risk of cancer.

Had we had the tech for personal nicotine vaporizers back in the 1600s [0] and retained it until today, I very strongly expect that -other than the "Drugs of all kinds are bad!" moralizers- you'd not see much of that sort of concern.

Besides, nicotine withdrawal is utter hell.

Waaaay back when when I quit cold turkey after smoking for a couple of years I was very grouchy and irritable (and knew that a cigarette would fix it) for like a week. That was it. I've not tried nicotine vaporizers, but I'd be interested to see if -given similarly sized nicotine doses- quitting vaporized nicotine after a couple of years is as annoying as quitting cigarettes was.

Caffeine withdrawal usually is solved by a night of good healthy sleep...

That tells me that you haven't gone through serious caffeine withdrawal. The effects from quitting caffeine cold turkey last for less time, but way more unpleasant than quitting cigarettes.

[0] ...or whenever tobacco smoking started to become A Thing...

1h agoHN ↗

Really? I don’t see anything objectionable in the article - and ‘an entire generation??’ How do you figure?

2h agoHN ↗

I think a big reason for this is that PDF editing tools are just pretty terrible.

PDFs are meant to be a presentation document format, not an editable document format. I have some experience editing PDFs, and it's difficult to make significant modifications. Editing small sections of text or replacing a date is fine, but once you try to start editing entire paragraphs or changing the layout, it quickly becomes unmanageable. The kerning looks weird, the spacing between words looks off, and when you look into it you realize the the sentence you're trying to edit is actually split across a dozen text objects. For these it becomes almost impossible to edit without destroying the spacing, so you just give up.

And the approved way to edit these PDFs is via Adobe Acrobat Pro, which costs $20/month (ugh), which I'm not willing to pay for.

So I think this is why we just don't see that many PDF forgeries. The editing tools just aren't very good. Maybe it's different now we can just ask Claude to edit our PDFs for us.

2h agoHN ↗

PDF's are not Presentation Document Format. Should be "Portable".

1h agoHN ↗

Good to see you change it from "PDFs are Presentation Document Format" => "PDFs are meant to be a presentation document format". Next time, don't forget edit log..

1h agoHN ↗

The flip side to this is that when you do come across a forged PDF (and I have!), they can be really, really effective. Nobody expects them. There are usually tells in the metadata, but... there don't have to be.

1h agoHN ↗

I agree that you won't find forged PDF documents in the wild with any type of frequency, but they are forged in private settings. Forged or doctored bank statements are relatively more common. FinCEN identifies altered bank statements alongside W-2s, tax returns, gift letters, and employment information as examples of documents involved in mortgage fraud [1]. In March 2026, a mortgage loan officer was even charged by federal prosecutors with altering and creating bank statements to make borrowers appear qualified for a mortgage [2].

[1] https://www.fincen.gov/mortgage-loan-fraud

[2] https://www.justice.gov/usao-mdfl/pr/licensed-mortgage-loan-...

1h agoHN ↗

(Or better yet: upload it directly to Libgen/Sci-Hub and let everyone else redistribute it.)

Can this actually be done without an ISBN or DOI number?

1h agoHN ↗

Yes. Libgen/Sci-Hub have minimal metadata requirements. And they especially do not require ISBNs/DOIs because there are an incredible number of documents out there with neither one. It would be absurd to ban all pre-1970 books, and lots of journals to this day don't bother issuing DOIs.

45m agoHN ↗

Ok this one actually baffles me -- anyone have the energy to explain what I'm missing? The repeated concern about forged scientific papers doesn't really track, but that's what academic institutions are for, at least in part.

If someone were to share a preprint PDF that I don't believe, my instinct would be to double-check it against the institution associated with its publication. If it was never published then it's basically just a screenshot of a blog post.

Ohhh okay the opening makes more sense now. The blog above is publishing papers in form of blog posts as a protest against scientific publishing. I love the energy, but ruminating on how weird it is that so few people take advantage of the thing that you're weird for doing in the first place feels... obtuse?