[mlissner]

No, we worked with researchers that developed that kind of system, but didn't broadcast our work b/c the research was too sensitive. Seems the cat is out the bag now though.

I think the combination of AI and font-metrics is going to be wild though. You ought to be able to make a system that can figure out likely words based on the unredacted ones and the redaction's size. I haven't seen any redaction system yet that protects against this.

[vlovich123]

I thought glyph spacing attacks are an old idea; like I recall reading about such ideas 10-20 years ago unless I’m misremembering. Can you clarify why it was considered “too sensitive” if the whole point of this effort is to showcase these attacks?

[mlissner]

It’s a fine line. Most redactions are for the good, to protect someone or something. For example even in the Epstein files, where some redactions are being abused, most redactions are protecting victims.

If there’s a way to undo huge amounts of redactions, that’d certainly be a net negative. Sort of like if encryption were suddenly broken, you wouldn’t publish a paper saying so.

Our goal has always been to educate about the problem so that it can be addressed. We didn’t have resources to push on the font metrics approach, so we stayed mostly quiet about it.

[thangalin]

> I haven't seen any redaction system yet that protects against this.

The linked article suggests widening redacted areas more than needed with some randomization applied to the width. Strikes me that that wouldn't do much except add a few more possible solutions.

[vlovich123]

Yeah, the more robust protection is to widen to a constant. But in the general case that could require reflowing the pdf. But honestly single word redactions are really probably useless with cheap AI that can highly accurately fill in the gaps

[NoboruWataya]

This is going to be a disaster IMO because AI will just hallucinate what it thinks is the most probable redacted word and people will take that as gospel.

[PunchyHamster]

"don't redact or we will hallucinate something worse and make people believe it as gospel" is nice deterrent

[hahn-kev]

Maybe we should all just use mono-space fonts for everything