snorkerMar 4
What is stopping #signal from becoming interoperable with #chatmail relays (i.e #deltachat)? Is there anything that makes it infeasible or undesirable, other than being technically difficult? @signalapp
Show threadarvindMar 4

Even though both Signal and Deltachat are instant messengers, they are fundamentally different at the protocol level.

Deltachat uses email as a substrate. Signal doesn’t.

More importantly, Deltachat uses Autocrypt, based on PGP, for encryption, while Signal uses the Signal protocol for encryption.

Autocrypt at present does not provide forward secrecy, or post-quantum encryption. The Signal protocol provides both.

The two encryption protocols are likely incompatible with each other. PGP relies on long-term keys. The Signal double ratchet involves derivation of new keys for every message so that earlier keys cannot be calculated from later ones. Trying something similar with PGP keys raises a lot of potential issues, as you can see from this discussion.

So… even if the Signal organization decides to enable federation for the Signal messenger, I doubt they will federate with Deltachat chatmail servers as they are presently designed.

@newhinton @adbenitez @vagnretur @tchambers


#signal #SignalApp #DeltaChat
Autocrypt 1.1.0 documentation

Show threadarvind

Also: there seems to be a near-consensus among cryptographers that PGP is simply a disaster, and must be absolutely avoided for any purpose whatsoever.

Here, for example, are a few blog posts:

Note that these opinions are spread out over a decade, and they are unanimous. You can find many more blog posts by other cryptographers expressing similar opinions.

I think the combined weight of all these individual opinions will also play a role in Signal’s decisions. So you can be almost certain that Signal will never support or even touch any encryption based on PGP.


#signal #SignalApp #DeltaChat
What’s the matter with PGP?

Last Thursday, Yahoo announced their plans to support end-to-end encryption using a fork of Google’s end-to-end email extension. This is a Big Deal. With providers like Google and Yahoo onboa…

A Few Thoughts on Cryptographic Engineering
Mar 4 at 9:21pmWeb
Show threadDelta ChatMar 4
@dialecticalmusings We have more similar articles collected at https://support.delta.chat/t/controversial-article-about-email/3604 if you are interested.
Controversial article about email

I stumbled across this relatively recent article (2020) accusing secure email messaging of being just “role-playing.” Obviously I set out to read it because it intrigued me and I would like to discuss it with your opinion as well. I make a list of the passages that seem salient to me by adding my own thoughts: there is an accusation that pgp is not secure and it refers for example to the possibility of decrypting messages and there is a link to a list of problems. I can’t comment on that, t...

Delta Chat