Mastodawn

pb 🇺🇦15h ago

After three intense months of work from more than a dozen contributors, #deltachat 2.48 releases are rolling. Maybe the most feature-packed releases ever?

- "zero metadata" messaging

- native Audio/Video calls on Android and iOS, as well as UbuntuTouch

- Group and Channel descriptions

- A new background audio player

- Revamped Download-on-Demand

and, last but not least, the long-awaited next-generation of messaging resiliency through "multi-path" routing ....

https://delta.chat/en/2026-03-31-zero

Delta Chat: Zero metadata, group descriptions, native audio/video calls and much more!

With the latest 2.48+ releases, a chat message reveals close to zero metadata to servers. For cryptographers and messenger enthusiasts, here are the key points on how we turned email very close to ...

@delta havent you always been advertising “zero metadata”. now its zero-er? hmh

Delta Chat 1d ago

@zaire we minimized metadata in prior steps, but only this release goes all the way. Maybe read the post for more context.

@delta @[email protected] It doesn't really go "all the way" though. Just because the email address is random, it doesn't make it unbreakable: it's still a unique and persistent identifier.

@kbruen @delta that. the persistent email addresses have always been a concern of mine. they can be recorded, they can be tracked, what’s up with that

@kbruen @delta part of me feels like delta is so commited to staying “the email messenger” because of some sunk cost fallacy. dont get me wrong, it works, but theres so much extra working around flaws that wouldntve existed with a proper IM protocol that has to be done

@[email protected] @delta No. Using email as a backbone is one of the big selling points. Otherwise, there's dozens of apps out there. Using the email infrastructure brings advantages no other protocol can bring, such as censorship resistance.
That's not the issue here. For example, the blog post mentions multiple relays, but only one seems to be used for sending, which feels like that meme of a miner giving up right before reaching diamonds. If Delta Chat would send each message from a random relay, the problem would pretty much be solved. Alas, I have a love-hate relationship with Delta Chat, and I often find the choices of the devs puzzling.

Delta Chat 13h ago

@kbruen @zaire we are proceeding step-wise and aim to provide stable user experiences across versions. In the last section of the blog post https://delta.chat/en/2026-03-31-zero#maximizing-availability-and-resilience-through-multi-path-delivery we already sketch a path forward that includes switching sending relays. But we need to move and change an implementation, and cant just work on the idea level alone.

Delta Chat: Zero metadata, group descriptions, native audio/video calls and much more!

With the latest 2.48+ releases, a chat message reveals close to zero metadata to servers. For cryptographers and messenger enthusiasts, here are the key points on how we turned email very close to ...

@delta @[email protected] I've read the blog post. The last section doesn't say that you plan to have sending through random relays. Besides words that make the blog post feel like corporate slop ("research and iterative streamlining of multi-path operations"), what I gather from that section is that you plan to replace manually adding relays with automatically adding a relay after discovering it. If there will still be a primary relay where all the messages come out of, that doesn't address what I said, and it still provides metadata that users can be identified by.

dexternemrod 12h ago

I like the step-by-step approach.

As soon as address-randomization is reached, the next complaint is that only the same n-adresses are in the pool. So the next request is to let DC create its own addresses. Get me right: This would be an awesome feature, I just use this to demonstrate that this is the nature of iterative approaches and ongoing improvements.

@dexternemrod @delta @[email protected] I'm not complaining about iterative development, I'm complaining about the blog post being titled "Zero metadata, ...", the Fedi post having the bullet point "- "zero metadata" messaging", the reply saying "this release goes all the way".
Those are all incorrect, and the blog post text saying "close to zero metadata" sours the great achievement by introducing the shady vibe that asterisks and tiny texts in advertising gives.
The achievement of having removed so much metadata is great on its own, and I think misrepresenting it cheapens it and leaves a bad taste.

@kbruen @delta @dexternemrod yup, you should know better than such misleading advertising. you’ve no chance of competing with telegram there, and it’s not that you should try

Delta Chat 12h ago

@kbruen @dexternemrod @zaire in hindsight, maybe "zero metadata messages" would have been the more proper framing. Apart from the maybe too catchy tag the text goes into quite some details what "zero metadata" messages are about. We highlight in the "Telegram" section that while we are discussing about nitty gritty details of cryptographic terminology, they lure >1 billion users into thinking Telegram is secure ....

microplastic 11h ago

@delta @kbruen @dexternemrod @zaire Y'all. Don't even mention Telegram, we are trying to hold you to a higher standard than that dumpster fire

@delta @dexternemrod @[email protected] Absolutely. I just hope you can also see my point that, if you don't like it when Telegram does it, then you should also not lure people with somewhat misleading claims that are then clarified in the details.

dexternemrod 11h ago

That is correct, my post was unclear in that part. I leave it unedited, but please see it as corrected with that message.

@delta Wow! 🙌

Götz Hoffart 1d ago

@delta Ups, and what if i already enabled (and added) additional relays with 2.43 and I want to upgrade to 2.48 (where the rel-notes state "Ensure all your devices are upgraded to version 2.48 or later before enabling this feature.")

Delta Chat 1d ago

@goetz this should work fine but it's better to upgrade still. Some details are better co-ordinated. But nothing bad or irreversible should happen if you use 2.43 and 2.48 side by side.

Delta Chat 1d ago

@goetz You can "hide" all relays but one for now, this way all your contacts will send only to one relay and not trigger the bug in 2.43. This is actually done automatically during upgrade, by default all relays except the primary one are hidden right after upgrade, so you don't need to do anything.

Séverin Lemaignan 1d ago

@delta looks like an impressive release! Audio/video calls based on WebRTC 🤩 Congrats to the devs! imho, the last remaing hurdle for much greater reach for deltachat is contact discovery. Any plans/ideas about that?

Delta Chat 1d ago

@severin thanks! Unfortunately, it is not likely the apps will offer contact discovery themselves. It would bring #deltachat closer to being a social media app, and invite spam and abuse which we are not prepared to handle due to the decentralized nature of our efforts. We do not know, mediate or see any interactions between users, an providing central discovery would break that privacy property.

OnkelBobbyWhite 1d ago

@delta @severin When I recommend a Delta/Arcane, it's always one of the arguments why this is better than Whatsapp and Signal, and underlines the data protection is written big.

Kevin_Runforrest

@delta a job well done, I was waiting for the support for audio and video calls, thank you very much to the developers.

Peter Vágner 1d ago

@Onlykievv @delta Audio / video calls on android are lovely! In call UI is awesome, ability to toggle both camera and microphone is working. There is even ability to switch audio outputs (speaker / ear piece).

An improvement to the future would be even more integrated incoming call notification experience. It would be nice to reuse android system support for this part too, so we can mute the ringer sound by pressing volume button and accept the incoming call by using the headset button.

I mean both convenience and accessibility when describing this.

Currently accepting the call can be done either by tapping the buttons in the notification area or tapping incoming call entry in the incoming message list. That includes multiple steps. Showing incoming call popup similar to how other apps are doing it would be more accessible.

Please don't take this as a complaining. I like these advancements very much. This is how I am envisioning it to work for the future.

@delta please correct me if i’m wrong. from your post it sound like what you call “zero metadata” isn’t metadata resistant in the sense that it doesn’t leak timing patterns to relay/mta or network adversaries, right?

Delta Chat 1d ago

@jaseg yes, it's about message header metadata, and the fact that no cryptographic identities are visible on the transport layer, making it hard for hostile servers to track anything when users change relays. This blog post is not a security whitepaper, which we admittedly still need to update and produce.

@delta thanks for the clarification. speaking from my network security background, the whole timing leakage is what i’d call metadata and what your “zero metadata” thing is protecting (AFAIU timestamps and cryptographic identities) in a cryptographic protocol i’d consider straight up data, not metadata.

thinking about an average user of a secure comms tool, i’d expect they would be surprised to learn that something that is “zero metadata” still leaks timing and through correlation identities.

Delta Chat 1d ago

@jaseg in the very first sentence we try to clarify the scope, i.e. "With the latest 2.48+ releases, a chat message reveals close to zero metadata to servers." The key phrase here is "to servers", and we then detail all the data that was made invisible to the server.
If you want to discuss this further, it's maybe better done in a support forum post.

@delta but it reveals timing, which everyone but you considers metadata, to servers

Vint Prox 1d ago

@delta I swear I saw an incorrect diagram some hour ago, where Alice and Bob only use two of their relays, and while writing my own post I was like: "HUUUUH?". And now it's corrected.

Vint Prox 1d ago

RE: https://mastodon.ml/@vint/116326032648628266

@delta All set!

xeniax ⏚22h ago

@vintprox @delta thanks for a great Russian description, очень хорошо написали

@vintprox @delta thanks a lot to you and others for following and looking so closely and attentive ❤️ you were not looking wrong, however, it is corrected meanwhile :)

@delta congrats and thanks to everyone who worked on this 👏💖

Blue Luma 22h ago

@delta does DeltaChat use or intend to use a double ratchet encryption algorithm ?

@blueluma @delta yes, it is coming. see https://delta.chat/help#pfs

Blue Luma 5h ago

@r10s @delta of thanks, I'll wait until then to test deltachat then

Vsevolod 15h ago

@delta
I know people ask for video calls, but I liked the absense of the feature. It's ok now too.
Multipath routing is a great!

Is telephony e2ee? You only mention peer-to-peer and no mention of e2ee.

Well done, you guys are really advancing at a rapid pace!

And please no contact-discovery!

Delta Chat 12h ago

@chiefbongo yes, calls are end-to-end encrypted. Sorry for not making this more explicit. We also still have work to do to update docs and get everything stabilized 😅

Delta Chat 12h ago

@chiefbongo and no worries, contact discovery is more or less a no-go area, even though it is lightly discussed sometimes, but certainly not via a centralized server, let alone one that we would run.

@delta i've lost all my accounts and settings after updating in macos. it's fine because i had second device in a phone to transfer that back. but yeah that was scary

@pancake @delta thanks a lot for the report, we have a theory, how that could happen, i created an issue for that at https://github.com/deltachat/deltachat-desktop/issues/6177 - maybe you can confirm or refine the issue there

@r10s in my defense i would say that a previous update corrupted the account files and i had a backtrace electron everytime i quit the app. And now this is gone ^^

Adam Jurkiewicz 8h ago

@delta great!