11 ms·
It doesn't take much to read between the lines on those two statements. Feds have access to Signal if they want it, but are using it as filter paper against mos
by snypher 2y ago
It doesn't take much to read between the lines on those two statements. Feds have access to Signal if they want it, but are using it as filter paper against most attacks against the public etc.
- tptacek 2y agoThe "feds" do not have access to Signal, except by CNE attacks against individual phones. Signal's security does not rely on you trusting the Signal organization.
- snypher 2y agoIt's ok for someone to believe that, but I don't believe that. Unfortunately there is no practical way to verify it either.
- cosmojg 2y agoWhat are you talking about? Signal is open source, and its cryptographic security is trivially verifiable. If you don't trust the nonprofit behind it for whatever reason, you can simply compile it yourself.
- warkdarrior 2y agoIf you compile it yourself, can you still connect to the Signal servers?
- greyface- 2y agoAnd, even if you can connect with your own client, can you trust the server is running the code they claim it is? They were caught running proprietary server code for a time in 2020-2021. https://github.com/signalapp/Signal-Android/issues/11101#issuecomment-798900367 https://github.com/signalapp/Signal-Android/issues/11101#iss... / https://news.ycombinator.com/item?id=26715223 https://news.ycombinator.com/item?id=26715223
- tapoxi 2y agoBut the client is designed to not trust the server, that's why encryption is end-to-end. So does it matter?
- greyface- 2y agoIn some sense, no - the protocol protects the contents of your messages. In another sense, yes - a compromised server is much easier to collect metadata from.
- tptacek 2y agoMetadata, yes. Of course, the protocols, and thus all the inconveniences of the Signal app people constantly complain about, are designed to minimize that metadata. But: yes. Contents of messages, though? No.
- greyface- 2y agoIf Signal, the service, was designed to minimize metadata collection, then why is it so insistent on verifying each user's connection to an E.164 telephone number at registration? Even now, when we have usernames, they require us to prove a phone number which they pinky-swear they won't tell anyone. Necessary privacy tradeoff for spam prevention, they say. This isn't metadata minimization, and telephone number is a uniquely compromising piece of metadata for all but the most paranoid of users who use unique burner numbers for everything.
- tapoxi 2y agoYes. There's also libraries that do this, like libsignal.
- viraptor 2y ago> and its cryptographic security is trivially verifiable That's going quite far. Even with all the details of it documented and open, there's a relatively small number of people who can actually verify that both the implementation is correct and the design is safe. Even though I can understand how it works, I wouldn't claim I can verify it in any meaningful way.
- tptacek 2y agoMultiple teams have done formal verification of the Signal Protocol, which won the Levchin Prize at Real World Crypto in 2017.
- viraptor 2y agoSure, there are teams who have done it. But it's not trivial. The fact there's a price for it shows it's not trivial. If I choose a random developer, it's close to guaranteed they wouldn't be able to reproduce that. The chances go to 0 for a random Signal user. Alternatively: it's trivial for people sufficiently experienced with cryptography. And that's a tiny pool of people overall.
- tptacek 2y agoThe idea isn't that you do formal verification of the protocol every time you run it. It suffices for the protocol to be formally verified once, and then just to run that one protocol. If you thought otherwise, you might as well stop trusting AES and ChaCha20.
- greyface- 2y agoIt is possible for the core protocol to be tightly secure, while a bug in a peripheral area of the software leads to total compromise. Weakest link, etc. One-time formal verification is only sufficient in a very narrow sense.
- 2y ago
- ghostpepper 2y agoIt’s not practically open source though - how many people actually build it themselves and sideload onto their Android/iphone? How much effort would it be for the US government to force Google to ship a different APK from everyone else to a single individual?
- tptacek 2y agoI don't know, a lot? They could with the same amount of effort just get Google to ship a backdoored operating system. Or the chipset manufacturer to embed a hardware vulnerability.
- gertop 2y ago"Here's a court order, you must serve this tainted APK we built to the user at this email" VS "You must backdoor the operating system used on billions of devices. Nobody can know about it but we somehow made it a law that you must obey." Come on, that's not the same amount of efforts at all.
- devops99 2y agoThe cryptography is not where Signal is vulnerable. What Signal is running on, as in operating system and/or hardware that runs other embedded software on "hidden cores", is how the private keys can be taken. Anything you can buy retail will for sure fuck you the user over.
- tptacek 2y agoOh, so none of this has anything to do with Signal. Ok!
- devops99 2y agoIn theory, "none of this has anything to do with Signal", and you are correct ; but back over here in reality: Signal runs on these systems. Hence the security afforded by Signal is very weak in-practice and questionable at best.
- Intermernet 2y agoRetail hardware actually has a better track record at the moment than bespoke, closed market devices. ANOM was a trap and most closed encryption schemes are hideously buggy. You're actually better off with Android and signal. If we had open baseband it would be better, but we don't, so it's not. Perfect security isn't possible. See "reflections on trusting trust".
- devops99 2y agoBespoke but-not-really-bespoke closed-market devices made by the right people are very secure, but they are not sold to the profane (you). > ANOM was a trap Yes, ANOM was intended to be a trap. > and most closed encryption schemes are hideously buggy Yes they are. Hence some of us use open encryption schemes on our closed-market devices. > You're actually better off with Android and signal. I am better off with closed-market devices than I am with any retail device. > If we had open baseband it would be better And the ability to audit what is loaded on the handset, and the ability to reflash, etc. In the real-world all we have so far is punting this problem over to another compute board. > Perfect security isn't possible. Perhaps, but I was not after "perfect security", I was just after "security" and no retail device will ever give me that, but a closed-market device already has. > See "reflections on trusting trust". Already saw it. You're welcome to see: - https://guix.gnu.org/blog/2020/reproducible-computations-with-guix/ - https://reproducible-builds.org - https://guix.gnu.org/en/blog/2023/the-full-source-bootstrap-building-from-source-all-the-way-down/
- bryant 2y agoWell, if you're in a position where you can only put faith in someone else's word as to whether it's good for your needs (this is the vast majority of people), there's this: https://community.signalusers.org/t/overview-of-third-party-security-audits/13243 https://community.signalusers.org/t/overview-of-third-party-...
- fragmede 2y ago> Unfortunately there is no practical way to verify it either. discuss an exceedingly clear assassination plot against the President exclusively over signal with yourself between a phone that's traceable back to you, and a burner that isn't. if the secret service pays you a visit, and that's the only way they could have come by it, then you have you answer.
- buckle8017 2y agoSignal's servers have access to your profile, settings, contacts, and block list if the PIN you select has low security.
- tptacek 2y agoWhich is to say: in the worst-case plausible failure model for Signal, they get the same metadata access as all the other messengers do. OK!
- fragmede 2y agoThreema leaks no such metadata
- tptacek 2y agohttps://breakingthe3ma.app/ https://breakingthe3ma.app/ You want to use this, by all means.
- rkagerer 2y agoWere any/all of those vulnerabilities mitigated?
- antgiant 2y agoPer the link. Yes. Here the specific statement. Lessons Learned We believe that all of the vulnerabilities we discovered have been mitigated by Threema's recent patches. This means that, at this time, the security issues we found no longer pose any threat to Threema customers, including OnPrem instances that have been kept up-to-date. On the other hand, some of the vulnerabilities we discovered may have been present in Threema for a long time.
- tptacek 2y agoFor what it's worth, and obviously I could have been clearer about this: what's interesting about that link is the description of Threema's design, not the specific vulnerabilities the team found.
- devops99 2y ago[flagged]
- int0x29 2y agoWhile the statments are contradictory I wouldn't take it as sign of some vast conspiracy. I would just take it as a sign they are stuck needing to give out some kind of guidance to prevent foreign access. While they are a domestic police service they are also a counterintelligence service and thus need to provide some guidance there.