OX (OpenPGP for XMPP): A New OpenPGP XEP (opens in new tab)

I'll agree with most of those but the re: the last point I'll throw out a half-hearted nay-say and reply with "sort of". The guys at keybase.io is trying real hard to let "Johnny have crypto" + https://www.mailpile.is/ makes it pretty easy for a Mac user to enable GPG and Gmail. My concern is primarily user-adoption - i.e., Johnny doesn't know why he needs crypto, even after Snowden. The NSA et al are counting on that apathetic attitude to make their jobs easier. Out of the box Mailpile is a easy stop-gap solution while more appropriate ones come out.

You're totally right re: DHT and cryptohashes for identification being a fairly ideal solution. PeerJS/WebRTC (part of HTML5 -- supported by Chrome and Firefox) support NAT-busting and are fairly secure. I'm slowly piecing together a comm-project addressing the larger issue because I'm tired of being complacent, with the intention of funding it eventually off of Exchange add-ins dual-licensed as open as I can while ensuring organizations above the size of 250 employees have to pay licensing fees.

That being said, what protocol isn't over-complex which has worked out well? Either you have things like SMTP which are just spec'd out by one or two dudes and submitted as an RFC where tons of stones were left unturned (leaving such a mess w/r/t maildir vs mbox not to mention the whole end-user problem of authentication, if you remember the sysadmin hell of trying to configure pop-before-smtp and a bunch of other problems during the late 90s, my god, it was horrid) -- or you have an over-spec Java2EE situation where everything is over-specified to an insane degree that implementations take teams and teams to get full compliance.

I ask this sincerely, with no snark - what protocol should one build crypto into?

> xmpp ties your identity to the server you register with, when there's technology to tie your identity to a cryptographic hash (you can use DHT to find people)

I have to disagree on this. XMPP follows the same model as email, where your identity is tied to a domain name, and I think it is about as good model as possible in our current internet. The key is that you really really should have your own domain, which then allows you to switch service providers at will without disrupting your identity. Of course I admit that it is bit idealistic viewpoint.

>- public xmpp servers are shutting down one after the other

How fast and what is your source for this? There are 146 public Jabber servers listed on IM Observatory right at the moment:

* https://www.xmpp.net/directory.php

I've personally never used a public Jabber server because I want my Jabber ID to refer to my domain.

Thanks for sharing. There are some good arguments here,* particularly re: servers holding your registration info and some of the downsides of requiring servers for xmpp (though it also has some advantages—it's nice to be able to message someone not online).

*though I'm always a little anti-"pgp can't be used by normal users." If the situation requires the security that PGP provides, users can frequently be made to learn. (That being said, Glenn Greenwald couldn't be bothered to set up PGP to talk to Snowden until someone got him up to speed. [0])

[0]: https://theintercept.com/2014/10/28/smuggling-snowden-secret...

Given these points, what protocol(s) do you think is the best candidate for development?

OTR [1], Axolotl [2] and OMEMO [3] all provide Perfect Forward Secrecy, which in turn means that you can't (or should not be able to) read your archived messages. And with OTR can't send messages to offline contacts. OpenPGP does not provide this property, which allows you to read your encrypted messages in the archive as long as you have access to your OpenPGP secret key and it allows you to send messages to offline contacts.

1: https://otr.cypherpunks.ca/ 2: https://github.com/WhisperSystems/Signal-Android/wiki/Protoc... 3: http://conversations.im/omemo/

One reason is that OpenPGP is already widespread and you may use known OpenPGP key to establish shared secret and switch to OTR then.

Another reason is that OTR is not multi-party. mpOTR [1] was suggested by OTR authors (Ian Goldberg et al.), but I am not sure you can find at least one peer who has it installed, and it is not maintained. So for XMPP conferences you may still want to go with OpenPGP.

[1] https://dx.doi.org/10.1145%2F1653662.1653705

Sometimes you want non-repudiable messaging.

Works great. Definitely check it out. (I found Matrix after trying to write an XMPP client and becoming a giggly/teary-eyed wreck trying to parse out how many incomplete extensions I would have to implement to get multi-device working. Previously: [1]) I now use matrix daily from all of my devices, mobile and desktop alike.

They're also working on an Axolotl rachet implementation: https://matrix.org/git/olm/ It's not integrated yet, sadly, but I'm eagerly awaiting seeing it jump in as a first-class supported feature.

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[1]: https://news.ycombinator.com/item?id=9772968

An implementation that hides key management from the user (or abstracts it in someway—I guess you still do want longterm, but revokable, key use) could be nice, but then you get closer and closer to mimicking what OTR does. That being said, hard to complain that such a thing exists as an option for those that want it (especially when those seeking it might come across the pre-existing, problematic standard).

XMPP does not inherently support end-to-end encryption. He was probably referring to the transport security, from client to server. This is achieved by securing the connection with SSL/TLS. Most often, IRC does not even support that, although some IRC networks also allow clients to connect with SSL/TLS.

This transport security from your client to the server only secures the first hop. It does not prevent eavesdropping on server-to-server connections, or on the connection of the receiving user if they do not also use SSL/TLS.