5 ms·
A few problems with this: 1) Much (most?) of the time, participants don't get to verify their safety numbers, and in those cases you are at least trusting the
by DavidSJ 6y ago
A few problems with this:
1) Much (most?) of the time, participants don't get to verify their safety numbers, and in those cases you are at least trusting the server to deliver your messages to the right client. There's a potential vector for man-in-the-middle attack (witting or unwitting) on the server side which shouldn't be dismissed here just because users are "supposed to" verify safety numbers.
2) Their behavior regarding server software might be predictive of their behavior regarding client software in the future. Given network effects, it might not be so easy to leave the Signal ecosystem in the future if your social network is on it, so it's worth knowing right now that it's possible that in the future the client software will also be closed-source.
- FourthProtocol 6y ago"..trusting the server to deliver your messages to the right client." This is where I feel a little unsure about Signal. It wants access to my contacts, and so it is possible to poison my contacts to get a rogue recipient into Signal. I would like a Signal in which I have the option to manually add contacts. Ideally a hash or key exchange or something, maybe a la PGP...
- tptacek 6y agoPGP has one of the worst metadata stories in all of secure messaging.
- FourthProtocol 6y agoTrue but not quite my point.
- grep_name 6y agoCan you elaborate what you mean by this?
- FourthProtocol 6y agoHe means that key exchange is frought with trust issues online. An exchange in meat-space is (can be!) 100% reliable, but doesn't scale. PGP is a posterchild for the impracticality of public key crypto. The UK actually made it work in conjunction with identity federation through the Government Gateway, but then the Government Digital Service got hold of it and destroyed any chances of moving it forward. Having seen it work I believe PKI can be practical at scale. And this is why I'd hoped a chat app might break some ground here.
- tptacek 6y agoNo, this is not at all what I mean.
- FourthProtocol 6y agoThen pray tell good sir.
- tptacek 6y agoMetadata problems in messaging systems are about what data about the communication leaks.
- FourthProtocol 6y agoSorry, I suspect I'm missing something obvious. You specifically said PGP, which is an encryption program that provides cryptographic privacy and authentication for data communication. And above you're saying it's about meta data problems in messaging systems. What is PGP's bad meta data story you were referring to?
- tptacek 6y agoWe're into the weeds here on this thread but the search bar below will avail.