https://www.argeliuslabs.com/deep-research-on-pdf-redaction-...
> Information Leaking from Redaction Marks: Even when content is properly removed, the redaction marks themselves can leak some information if not done carefully. For example, if you have a black box exactly covering a word, the length of that black box gives a clue to the word’s length (and potentially its identity).
Does X-ray employ glyph spacing attacks and try to exploit font metric leaks?
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?
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.
> 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.
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
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.