apyrgiotis

(disclaimer: one of the Dangerzone devs)

That's something I do from time to time as well. AFAIK Google Drive renders all documents on the server-side (which implicitly means that they don't trust the browser sandbox), so that's a reasonable price to pay for less privacy.

Dealing with sensitive documents though is another story, you just can't upload them to a third-party service. That's where projects like Dangerzone come into play.

Oof, that's a great point. We briefly touched on this a few weeks ago, but from the angle of canary tokens / tracking pixels [1].

Security-wise, our main concern is protecting people who read suspicious documents, such as journalists and activists, but we do have sources/leakers in our threat model as well. Our docs are lacking in this regard, but we will update them with information targeted specifically to non-technical sources/leakers about the following threats:

- Metadata (simple/deep)

- Redactions (surprisingly easy to get wrong)

- Physical watermarking (e.g., printer tracking dots)

- Digital watermarking (what you're pointing out here)

- Fingerprinting (camera, audio, stylometry)

- Canary tokens (not metadata per se, but still a de-anonymization vector)

If you come in FOSDEM next week, we plan to talk about this subject there [2].

The goal here isn't to provide a false sense of security, nor frighten people. It's plain old harm reduction. We know (and encourage) sources to share documents that can help get a story out, but we also want to educate them about the circumstances in which they may contain their PII, so that they can make an informed choice.

[1]: https://social.freedom.press/@dangerzone/115859839710582670

[2]: https://fosdem.org/2026/schedule/event/JZ3F8W-dangerzone_ble...

(Dangerzone dev btw)

Hey, Dangerzone dev here. Just wanted to say that the temporary input file is actually within a sandbox - and there's one sandbox per file - so there's no collision with other files in the host.

> Someone could potentially use the underlying tools directly in their own needs workflow, or an expert in those tools could mention if there's a vulnerability / common mistake pattern.

Yep, that's something we cover in our about page. We process the untrusted document in a gVisor sandbox, that runs within a hardened Linux container, that runs within a Docker Desktop VM (in Windows/macOS). And yet, that doesn't mean that Dangerzone can't get hacked by a determined (possibly state-backed) attacker. So yeah, you have a point.

At the same time, using tools like this raises the "you must be THIS determined to enter" bar. This means attackers must spend much more money, time, expertise, 0-days, etc. These resources are finite, so more people are protected as a net result, even if we can't protect everyone. That's the way I see it at least.