Technology

So Signal does not have reproducible builds, which are very concerning securitywise. I talk about it in this comment: https://programming.dev/post/33557941/18030327 . The TLDR is that no reproducible builds = impossible to detect if you are getting an unmodified version of the client.

Centralized servers compound these security issues and make it worse. If the client is vulnerable to some form of replacement attack, then they could use a much more subtle, difficult to detect backdoor, like a weaker crypto implementation, which leaks meta/userdata.

With decentralized/federated services, if a client is using other servers other than the "main" one, you either have to compromise both the client and the server, or compromise the client in a very obvious way that causes the client to send extra data to server's it shouldn't be sending data too.

A big part of the problem comes with what Github calls "bugdoors". These are "accidental" bugs that are backdoors. With a centralized service, it becomes much easier to introduce "bugdoors" because all the data routes through one service, which could then silently take advantage of this bug on their own servers.

This is my concern with Signal being centralized. But mostly I'd say don't worry about it, threat model and all that.

I'm just gonna @ everybody who was in the conversation. I posted this top level for visibility.

@[email protected] @[email protected] @[email protected] @[email protected] @[email protected]

EDIT: elsewhere in the thread it is talked about what is probably a nation state wiretapping attempt on an XMPP service: https://www.devever.net/~hl/xmpp-incident

For a similar threat model, signal is simply not adequate for reasons I mentioned above, and that's probably what poqVoq was referring to when he mentioned how it was discussed here.

The only timestamps shared are when they signed up and when they last connected. This is well established by court documents that Signal themselves share publicly.

This of course, assumes I trust the courts. But if I am seeking maximum privacy/security, I should not have to do that.

Signal is under control by the government? 🤔

Signal doesn't suffer anything worse than DoS if a hostile party controls the central service. That's its point and role. It's based on the assumption that such hostile parties as governments don't like DoS'ing central services, they prefer to be invisible.

For other points and roles other solutions exist. One can't make an application covering them all, that never happens.

Briar again (I've finally read on it and installed it, and I love how it works and also the authors' plans on the future possibilities based on the same protocols, but not for IM, say, there's an article discussing possibility of RPC over those, which, for example, can give us something like the Web ; I mean, those plans are ambitious and if I want them to succeed so much, I should look for ways to defeat my executive dysfunction and distractions and learn Java). Except it would be cool if it allowed to toss data over untrusted parties, say, now if two Briar users in the same group are not in each other's range, but there's a third Briar user not in that group between them, their group won't synchronize (provided they don't have Internet connectivity). If one could allow allocating some space for such piggybacked data, or create some mesh routing functionality, then it would become a bit cooler.

End to end encryption between clients (also for groups) seems to partly address the issue of a bad server. As for self-hosting, any rented or cloud sevices are very vulnerable to an evil maid. So either in-house hosting or locked cages with tamper-proof hardware remain an option.