[brobinson]

Threema is not open source yet so I wouldn't use it for that reason. I did like their security whitepaper, though, and they do have some impressive clients (Mercedes-Benz, etc.).

[soziawa]

Additionally they have regular audits [1]. Open source only without any actual thorough reviews doesn't cut it in my opinion.

[1]: https://threema.ch/en/blog/posts/audit-2020-en

[viccuad]

Open source is a precondition. They can promise you the world, but if you can't build it yourself and get reproducible builds, who knows what's in there.

[robert_foss]

Yeah, agree. We've had enough fun recently with the likes of the CIA backed Crypto-AG.

[soziawa]

Sure, but a precondition itself doesn't guarantee anything. You still need to pony up the money for actual aufits.