> Perhaps we'll see a good distributed peer to peer messaging protocol at some point in the future.

The Matrix protocol is actually fairly promising, as long as you only use it for Matrix<->Matrix communication. Things fall to pieces when you try to bridge it with IRC.

It's certainly more user-friendly for non-tech. folks than, say, the awkward key exchange/setups of XMPP clients, but it's still a far cry from something like Signal in terms of 'ease of use'

> awkward key exchange/setups of XMPP clients

What do you mean by that? Conversations.im establishes e2e secure session without any fingerprint approving interaction whatsoever. Of course you can manually scan barcodes for paranoid mode but that's not necessary.

For me it's a perfect balance between convenience and security. Read more at https://gultsch.de/trust.html

Hmm, I'll check this out, thanks.

I was mainly speaking to previous experiences trying to set up Conversations on one device, Pidgin on another, there not being any good way to use a consistent key for my user on both, and trying to walk non-technical family members through that fiasco. This was about 2 years ago, maybe the situation has improved!

Keep in mind that Pidgin supporting many protocols means "lowest common denominator" in several cases. For OMEMO E2E I'd recommend Gajim or (still in alpha but promising) dino.im

You can check on the progress of Omemo support for the various XMPP clients here:

* https://omemo.top/

Doesn't matrix do everything through federated servers?

There are more entities we have to trust in this matter. For example when I download whatsapp on my phone I trust that Google hasn't injected its own spyware into the binary, because there is no way for me (as an end-user who doesn't want to hack my own phone to get root access) to verify that the binary came directly from whatsapp.

As much as Jobs revolutionized the smartphone industry, this is the long-lasting legacy we will have to live with for decades (or forever?).

I'm no expert but GNU Ring https://www.ring.cx does look interesting. It doesn't give the federated goodness that Matrix does, but is truly distributed P2P using DHT. It was absorbed by GNU in 2016, so it does have that going for it.

There is Briar which is peer-to-peer and uses Tor (or even just Wifi):

https://briarproject.org/

Decentralized private messaging doesn't sound too hard. With the e2e encryption that already exists it doesn't seem to difficult to add more servers as you don't really need trust in the first place.

I could be wrong though.

To maybe clarify what dasil003 means, state-of-the-art encryption for this requires that everyone has a pair of keys, one of which they keep a secret - their Private Key, and one of which they tell all of their friends, acquaintances, everyone who might ever want to communicate with them - their Public Key.

And then if you want to talk to them, you encrypt your message with their Public Key. Then only they can decrypt it with their Private Key (assuming no one else their Private Key).

But if a hacker / NSA agent / script kiddo pretends to be your friend and tells you their Public Key, then they'll be able to decrypt your messages with their Private Key. You might never know that they aren't your friend.

You'll have to ensure that you actually have the Public Key of your friend by some other method. For example meet them in person to exchange Public Keys, or read it out over the phone, if you know what their voice sounds like on the phone.

Ok so the issue is authentification of the identities. This doesn't seem to be a solved problem in any space, even HTTPS is vulnerable to this kind of attack.

It could be decentralized through pluggable identity authorities which provide the public key transfer via a secure channel. Essentially you'd use the same protocol and select what servers (WhatsApp, Signal, maybe some sort of immutable ledger elsewhere) to use.

It is solved, but the solutions all involve a mutally trusted third party.

You always need trust, how do you know you're talking to your friend?

Side channels are the only way, practically speaking. Call them and have them read off the hash of their key and verify it against the key you received from "them". Or have them send a nonce value through the system to you that you provided over a side channel.

Any time you have a central authority providing that validation, you have to trust that your "friend" hasn't fooled them.

The theory with Signal is that you might verify their identity in meatspace, or some other way. But yes, it's definitely an interesting chicken and egg problem. As far as the thought exercise goes, it might be worth limiting your scope at this point.

Threema has a system where contacts are verified using a QR code scan: https://threema.ch/en/faq/levels_expl These three dots are shown throughout the UI, so with the identity of a contact you always see the trust level.

This is much easier to explain to a non-techie than comparing security numbers or hashes.

- Red = No trust

- Yellow = You trust that the server has verified the identity

- Green = You have verified the identity yourself

(Edit: Formatting)

Opinions about giving this trust matter to dedicated certificate authorities instead, like we do with HTTPS?

Edit: Found the problem with that. Certificate authorities are supposed to actually go out and confirm that the person who requested the certificate, is the person that they say they are. This is far too much work, if you want to verify each individual person who wants to use a messenger.