[HN Gopher] Delta Chat is a decentralized and secure messenger app
       ___________________________________________________________________
        
       Delta Chat is a decentralized and secure messenger app
        
       Author : Bluestein
       Score  : 227 points
       Date   : 2025-06-21 06:29 UTC (16 hours ago)
        
 (HTM) web link (delta.chat)
 (TXT) w3m dump (delta.chat)
        
       | fouronnes3 wrote:
       | I'm curious how spam protection works if you're an alternative,
       | few users, chat app? I hate Meta's monopoly as much as the next
       | guy but one thing you do have to credit them for is the second to
       | none spam protection. I also wonder how much requiring a cell
       | number is part of that strategy.
        
         | chrisldgk wrote:
         | I wouldn't necessarily agree that WhatsApp's spam protection is
         | that great. I've been invited to quite a lot of pyramid
         | scheme/scam WhatsApp groups, however that's mostly happened
         | after having to expose my private cell number on the internet
         | (thanks to app stores and GDPR requiring some kind of phone
         | number for businesses of any size).
        
           | Bluestein wrote:
           | ... always wondered if the cell phone requirements are not
           | (also) tied to then wanting an actual, physical, person
           | behind each account - as in most EU jurisdictions each SIM
           | card is tied to an actual ID.-
        
             | marci wrote:
             | In many EU countries, you can buy sim cards from some
             | vending machine, in a grocery store or places where you can
             | buy international telephone cards. No ID required. But
             | phone plans are often tied to your home internet.
        
               | em-bee wrote:
               | are you sure no ID is required to activate the cards? at
               | least in austria and i believe in germany you can't get a
               | sim card without an ID.
        
               | marci wrote:
               | If you get a lyca sim card, even there you don't need ID
               | to use it. There might be some restrictions after a month
               | though.
        
             | Bluestein wrote:
             | Ah, the EU -- land of fine cheeses, indecipherable GDPR
             | popups, and, of course, the iron-fisted grip on your humble
             | little SIM card. In the EU, you can't even sneeze near a
             | prepaid phone number without showing at least three forms
             | of government-issued ID, a notarized statement of purpose,
             | and possibly a blood sample. Why? Because buying a SIM card
             | anonymously here is about as legal as fencing stolen
             | paintings in the town square.-
             | 
             | You see, most EU countries decided some time ago that
             | allowing people to own mobile numbers without a background
             | check was simply too dangerous. What if someone used a
             | burner phone to commit fraud, or worse -- say something
             | mildly controversial on the internet? To prevent such
             | dystopian chaos, SIM registration laws were born. Now,
             | whenever you purchase a SIM card in France, Germany, Spain,
             | or pretty much anywhere with croissants, you have to offer
             | your passport, soul, and, ideally, a letter of
             | recommendation from your local constable.-
             | 
             | The result? Your phone number in the EU is no longer just a
             | string of digits--it's basically your name, address, and
             | social security number all rolled into one. It's like a
             | little snitch in your pocket, ready to identify you at the
             | first sign of online mischief. Online platforms know this.
             | That's why so many of them, from social networks to AI
             | models, insist on a phone number. They're not just trying
             | to text you cute security codes -- oh no, they're trying to
             | make sure there's a warm, squishy, legally-recognizable
             | human on the other end. Preferably one without too many
             | fake Twitter accounts.-
             | 
             | Technically, GDPR is supposed to protect your data. That
             | includes your phone number. But there's a loophole the size
             | of Luxembourg: if the phone number is used to stop
             | terrorism, fraud, bots, or people being mean in the
             | comments, then suddenly it's all hands on deck. Platforms
             | benefit from the comforting knowledge that EU phone numbers
             | are like digital dog tags: traceable, trackable, and just
             | annoying enough to prevent the average troll from spinning
             | up 50 accounts to yell into the void.-
             | 
             | Of course, this all raises philosophical questions. Like:
             | should your right to privacy hinge on your desire to play
             | Candy Crush in peace? Is a SIM card a person? Could it run
             | for European Parliament? And should we perhaps explore more
             | civilized alternatives to this "one phone number equals one
             | identity" system, like zero-knowledge proofs or just asking
             | nicely?
             | 
             | In the meantime, welcome to the EU: where the cheese is
             | soft, the bureaucracy is hard, and your SIM card knows more
             | about you than your therapist.-
        
               | data_maan wrote:
               | Nice post, I smiled.
               | 
               | There are several countries that didn't buy into the
               | madness of registering SIMs, luckily. Most strangely, the
               | UK, the master of CCTV. Apparently they realized that
               | it's a useless measure and will just anger the people.
        
               | Bluestein wrote:
               | ... And SIMs are available from vending machines, which I
               | find amusing :)
        
           | radiospiel wrote:
           | afaik no businesses are required by the gdpr to collect phone
           | numbers, and would like to see evidence otherwise
        
             | progval wrote:
             | There are no occurrences of "cell" or "phone" in GDPR, and
             | the only relevant occurrences of "number" are about
             | "national identification numbers", which phone numbers are
             | not.
        
             | chrisldgk wrote:
             | Sorry, I should have been more specific. In Europe (or
             | Germany at least) it's required by law that you provide an
             | imprint with contact information for every site you host,
             | as well as a privacy policy that includes contact
             | information of your GDPR officer if you collect any kind of
             | personalized data. Since I'm a one-person company, that
             | includes my personal phone number since I don't have a
             | business phone. Also chrome webstore for example requires a
             | phone number if you host an extension on there.
             | 
             | Edit: Also this wasn't about collecting phone numbers, but
             | about providing one for your business if you host a
             | publically accessible site
        
         | v5v3 wrote:
         | An alternative few users chat app probably won't be a major
         | target for spam untill it has lots of users.
         | 
         | So I would say it's a low priority feature in the backlog.
        
         | XorNot wrote:
         | If your need is security then really that should be based on in
         | person trust.
         | 
         | Or at least via a proxy.
         | 
         | So contact invitation can just be handled with use-once codes
         | (or at least trivially burnable ones).
        
         | msgodel wrote:
         | It's just email and gpg so you'll get the same spam you do
         | normally.
         | 
         | IMO people freak out about spam way too much. I'd rather have
         | something that works with occasional spam than have to put up
         | with the insanity of modern IM. Having push notifications from
         | 10 proprietary IM apps is worse spam than a couple of emails a
         | day from some retard trying to get me to download a "pdf." I
         | don't block spam at all in my personal email (although I have a
         | couple of tools automatically label it.) I'd rather have
         | everything delivered.
        
           | em-bee wrote:
           | i run my own email server, using a spam filter i set up years
           | ago without explicit blocking (only tagging and filtering)
           | and didn't touch it since. the amount of spam i get is
           | negligible. a few false positives, but nothing serious. in
           | fact it's so little i could probably just leave all the spam
           | in the inbox. it is tagged as spam anyways.
        
             | immibis wrote:
             | I have my own email server with a wildcard address (I still
             | use gmail for anything that's actually important). I put
             | certain addresses in shady forms a few times. I get a
             | couple of spam messages per day to those addresses - always
             | the same spam few spam campaigns. One is offering to sell
             | me electric bicycles or partner with me to sell electric
             | bicycles (didn't really pay attention) and more recently I
             | started getting business proposal advance fee spam. The
             | volume is pretty manageable and if I wanted, a pretty
             | simple filter tuned for the spam I actually get would catch
             | all of it and no ham.
             | 
             | I got spam to postmaster once for some reason. That's a
             | nice way to make admins aware of your spam campaign.
             | 
             | Spam is presumably more of a problem when you're more well-
             | known and you don't have the option to control your own
             | filters.
        
         | ravdeepchawla wrote:
         | You can design your way around it
         | 
         | 1. Manually screen who can send you messages like Hey[^1] and
         | Apple[^2]
         | 
         | 2. Basic filtering to ensure the promotional stuff gets blocked
         | or put in a separate list [^3]
         | 
         | 3. Rate-limit senders who are showing robot like behaviour
         | 
         | ---
         | 
         | [^1]: https://www.hey.com/features/spam-corps/
         | 
         | [^2]: https://support.apple.com/en-
         | il/guide/iphone/iph203ab0be4/io...
         | 
         | [^3]: https://f-droid.org/en/packages/spam.blocker/
        
         | em-bee wrote:
         | deltachat distinguishes between normal email and deltachat
         | messages. you can limit to the latter if you only use it to
         | communicate with other deltachat users.
        
       | sixtiethutopia wrote:
       | It's email-compatible and uses pgp for encryption. No forward
       | secrecy and supports sending unencrypted messages as well for
       | people who don't have pgp.
       | 
       | No forward secrecy and will automatically switch to unencrypted
       | messages if you receive an unencrypted message from a contact.
       | 
       | I wonder if it's vulnerable to downgrade attacks from adversaries
       | falsifying the sending address. If an adversary sends an
       | unencrypted email imitating a contact will delta chat reject it
       | or will it silently switch the chat with that contact over to
       | unencrypted email?
        
         | folmar wrote:
         | The way to have guaranteed encryped is creating two user
         | encrypted group chat.
         | 
         | https://delta.chat/en/help#how-can-i-ensure-message-end-to-e...
        
         | deknos wrote:
         | did you look into their spec? perhaps they used the updated
         | openpgp standard which has authenticated encryption. or perhaps
         | they just sign everything.
         | 
         | and it's not just pgp with email, it's more akin to an
         | overlaysystem.
        
         | maqp wrote:
         | >No forward secrecy and supports sending unencrypted messages
         | as well for people who don't have pgp.
         | 
         | JFC. There's a reason Signal dropped SMS support. What an
         | insane design decision.
        
           | joecool1029 wrote:
           | FWIW textsecure (signal's SMS predecessor) did provide
           | forward secrecy. Details are here:
           | https://signal.org/blog/asynchronous-security/
        
             | maqp wrote:
             | Yeah but it later also supported non-E2EE SMSs and those
             | were a security risk and they rightfully dropped the
             | support. It was not ideal your grandma thinks any message
             | sent in Signal is safe, when that wasn't the case.
        
       | HelloUsername wrote:
       | Previous discussions:
       | 
       | 05-mar-2025 https://news.ycombinator.com/item?id=43262510 100
       | comments
       | 
       | 24-jan-2021 https://news.ycombinator.com/item?id=25893626 148
       | comments
       | 
       | 07-jan-2021 https://news.ycombinator.com/item?id=25674894 4
       | commments
       | 
       | 27-feb-2019 https://news.ycombinator.com/item?id=19263357 11
       | comments
       | 
       | 21-feb-2019 https://news.ycombinator.com/item?id=19216827 56
       | comments
       | 
       | 03-feb-2017 https://news.ycombinator.com/item?id=13560279 1
       | comment
        
         | data_maan wrote:
         | Great source of info.
         | 
         | I wonder why this was downvoted
        
       | hkt wrote:
       | Used it for years, it is great. Webxdc apps work in both android
       | and desktop clients (not sure about iOS) so I can play chess,
       | share calendars and to do lists, and even collaboratively edit
       | documents, all by email, all privately.
       | 
       | Anyone who hasn't tried it really ought to.
       | 
       | To the haters talking about PGP: giving your entire social graph
       | to Meta or even Signal is considerably worse.
        
         | singpolyma3 wrote:
         | Besides the fact that hating on PGP is like hating on TLS. It's
         | a spec and a container for just about anything you want to do.
         | gnupg (the thing most people have come to dislike) isn't even
         | spec compliant anymore and was always a power user tool not
         | something most users should actually touch anyway
        
           | Avamander wrote:
           | Nah, hating on PGP is like hating on SSLv3. The specs are
           | bad, the entire system is very error-prone, and the
           | cryptography itself is also outdated.
        
         | rlue wrote:
         | How is the latency? All mainstream chat apps have low-enough
         | latency that a live conversation feels fluid and natural,
         | whereas I frequently encounter situations where I have to wait
         | up to five or ten seconds for an email to come through. That
         | kind of latency would kill the experience IMO.
        
           | em-bee wrote:
           | in my experience the "latency" for a person to reply to a
           | message is always higher than the latency for a message to
           | arrive. in fact, some latency is good. gives you a break to
           | think.
        
       | shark_laser wrote:
       | Why not 0xchat?
       | 
       | Private key login, encrypted private chats and contacts,
       | encrypted group chats, and lightning payments. Decentralised,
       | built on Nostr. Available on all platforms.
       | 
       | https://www.0xchat.com/
        
         | data_maan wrote:
         | 0xchat on the surface seems better: looks like a professionally
         | maintained codebase, with clear ways to interact with the devs.
         | 
         | But - has there been security audit been done?
        
         | rpdillon wrote:
         | I think the point here is that everyone has email. A chat
         | client built on Nostr is fine (and I want to love Nostr), but
         | it just doesn't have the reach or ubiquity of email.
        
           | AJ007 wrote:
           | When you start looking at alternative messengers outside of
           | Matrix, XMPP, and IRC, there isn't much where third parties
           | can operate or implement both servers and clients.
           | 
           | Certainly if no one can implement these two things it is
           | functionally a closed source project. It also is a security
           | failure from the standpoint of control, validation, and also
           | future security and vulnerability patching (there's a
           | graveyard of dead "secure" messaging apps.)
           | 
           | Is DeltaChat perfect from a security standpoint? No, but it's
           | certainly well above the hurdle most people are at now. Most
           | people are using non-encrypted communication that is actively
           | scanned & stored, or e2e on paper stuff where one party
           | controls the client, server, application, and storage (trust
           | me e2e security.)
           | 
           | Telegram, Discord, Facebook Messenger, stop using that shit.
        
             | promptdaddy wrote:
             | Apologies for any nativity here, but wouldn't storing
             | encrypted messages on a blockchain be a robust solution for
             | this?
        
               | heavyset_go wrote:
               | Why would you want that? The last thing I'd want in a
               | secure messenger is a permanent ledger that holds message
               | content and associated metadata which anyone can analyze.
               | 
               | edit: I didn't downvote you and I don't think someone
               | asking an honest question like this should be downvoted
        
             | maqp wrote:
             | >Is DeltaChat perfect from a security standpoint? No, but
             | it's certainly well above the hurdle most people are at
             | now.
             | 
             | It's less safe compared to Signal, and Signal is the gold
             | standard recommendations for average Joes. "Better than
             | Telegram" is a low bar.
        
               | em-bee wrote:
               | telegram is the most user friendly chat out there. the
               | only ones that compete in usability are wechat (yes, the
               | chinese one) and, deltachat. signal just got a bit better
               | by finally allowing me to hide my phone number. of all
               | these, deltachat is the only one that doesn't require a
               | smartphone and a phone number.
        
               | maqp wrote:
               | >telegram is the most user friendly chat out there.
               | 
               | Telegram is a walking time bomb with 900 million users'
               | data waiting to be leaked from the servers.
               | 
               | >and, deltachat.
               | 
               | That must be why I've never heard of anyone using it.
               | 
               | >deltachat is the only one that doesn't require a
               | smartphone and a phone number.
               | 
               | It leaks the IP-address to the server, which by default
               | (defaults matter) is nine.testrun.org. That server can
               | amass metadata about users conversing, and any government
               | entity that comes knocking can look at TelCo records
               | about to which user the IP-addr was assigned at the time.
               | 
               | If you're going to try to address metadata privacy
               | against service provider, you're going to have address it
               | properly, and DeltaChat isn't the one at that point.
               | Neither is Signal. You'll want Cwtch for that.
        
               | em-bee wrote:
               | nine.testrun.org is owned by deltachat developers. it is
               | about as trustworthy as, say, matrix.org. the only better
               | alternative would be self hosting.
               | 
               | the question is not what is the best, most secure, most
               | private, option, but what has the right balance between
               | easy onboarding, ease of use, security and privacy. and
               | maybe deltachat is not the best possible, but it is
               | pretty good. remember, when security and privacy are to
               | onerous then you don't have security or privacy because
               | people will refuse to use the tool.
        
               | maqp wrote:
               | >the only better alternative would be self hosting.
               | 
               | Which doesn't really work in practice. The closer you
               | move to the user, the more the threat of creepy buddy
               | watching over metadata of people they know grows. Medium
               | sized institution like university or a company might run
               | their own, but that's also somewhat risky.
               | 
               | >the question is not what is the best, most secure, most
               | private, option, but what has the right balance between
               | easy onboarding, ease of use, security and privacy.
               | 
               | No. The question is, given an architecture that imposes
               | fundamental limitations on what can be achieved, which
               | tools under that domain have best privacy by design
               | system, where the UX and features are maximized with
               | ingenious design, is the best.
               | 
               | Fundamental architectural limitations:
               | 
               | Does Delta Chat use data diodes? No? Then it can't have
               | key exfiltration security, but it can have message
               | forwarding.
               | 
               | Does Delta Chat use Tor Onion Services? No? Then it can't
               | have proper metadata privacy for users' identity from the
               | server, but it can have offline messages.
               | 
               | These are fundamental trade-offs.
               | 
               | DeltaChat is content-private by design. It might be
               | metadata-private by policy (internal policy that server
               | on nine.testrun.org does not collect metadata), but until
               | that is tested in court like Signal is, we can't know for
               | sure.
               | 
               | Signal is content-private by policy. Cwtch uses Tor Onion
               | Services so it's metadata-private by design.
               | 
               | Now, it's fine to argue which is the best inside one
               | league.
               | 
               | Element/Matrix is E2EE with double ratchet protocol, so
               | it has both forward secrecy and future secrecy, which
               | DeltaChat doesn't have.
               | 
               | It's only once security is more or less exactly on par,
               | that you should be comparing general UX. Really usable
               | but insecure tool might turn into really unusable tool
               | when you sit in prison for your political opinions, or
               | because you revealed your ethnicity and ICE caught on.
               | 
               | >maybe deltachat is not the best possible, but it is
               | pretty good
               | 
               | It's not the worst out there. At least it tries to do
               | things properly. It's just that given that there's insane
               | obstacle of moving people to a safe platform, DeltaChat
               | is just another distraction. Until it does what
               | competition does security wise, and improves on their UX,
               | it doesn't get the top podium.
               | 
               | >when security and privacy are to onerous then you don't
               | have security or privacy
               | 
               | Sure, but when you're in prison for using crap tool, you
               | won't have liberty, security, or privacy.
        
               | em-bee wrote:
               | _It 's only once security is more or less exactly on par,
               | that you should be comparing general UX._
               | 
               | ideally yes, but that is not what the average user will
               | do, and it is not what i can use as an argument to get
               | people to switch to something more secure. convenience
               | over security is still a user preference.
               | 
               | i get your point, but that falls on deaf ears among
               | family and friends. especially using prison as an
               | argument is really not helping. i mean by the same
               | argument we should not be having this conversation on
               | hackernews, because clearly we are trying to subvert the
               | authorities by suggesting that people should keep their
               | communication secret.
        
           | lxgr wrote:
           | Nor does Delta. Nobody will "chat" with me via their Gmail
           | email focused UI, so it's effectively a separate network
           | anyway.
           | 
           | Using an email _address_ as an _identifier_ for IM is a great
           | idea (I hate that everything uses phone numbers for this,
           | which are not internationally portable and not possible to
           | reasonably "self-custody" the way TLDs are).
           | 
           | But using the actual email protocol as a backing protocol for
           | instant messaging seems like a weird contortion and still
           | makes this effectively a separate protocol, the split being
           | servers that do and don't support all necessary extensions.
           | The overhead must also be staggering; just look at an email
           | header to see how much is going on for each message these
           | days.
        
             | em-bee wrote:
             | you got a point with the overhead in email headers. also an
             | email is sent not only for every message but also status
             | updates. that adds up to a lot of emails.
        
         | maqp wrote:
         | https://github.com/0xchat-app states it doesn't have desktop
         | clients.
         | 
         | Also, the direct messages have three types
         | 
         | 1) NIP-04 DM: "Most widely used", but also, "not recommended".
         | Reeks of Telegram that also has non-secret chats being the most
         | popular option
         | 
         | 2) Gift-Wrapped DM: Uses different encryption algorithm but no
         | forward secrecy? Forward secrecy has been around for 20 years.
         | 
         | 3) Secret DM: Can't be recovered on different devices. Why
         | can't the backup be self-contained database like Signal has?
         | 
         | Also "Secret chat requires consent from peer." Like what :D You
         | have to wait for contact's approval to have a private
         | conversation with them. Sounds like it incentivizes all chats
         | to start with less secure protocols.
         | 
         | The nice part about writing your own chat system is the
         | security agility in that you can bump any security property
         | without having to fight with protocol standardization bodies.
         | Having three DM protocols inside the same app is wild.
        
         | heavyset_go wrote:
         | Doesn't Nostr expose the fact that you sent messages to certain
         | people via its blockchain?
        
       | data_maan wrote:
       | How does this (or 0xchat) compare to Signal?
       | 
       | Have their been done any third-party security audits by reputable
       | companies?
       | 
       | If not, it's not safe to use - who knows what's buried in the
       | source code (even if the source code is open).
        
         | johnisgood wrote:
         | I mean, should probably just use Ricochet Refresh, Briar,
         | Session, Element, etc.
         | 
         | I also built OTR on top of Discord but it requires Nitro
         | because the messages for OTR end up being way too long. :(
        
           | progval wrote:
           | Can't they be split into lines? OTR was designed for IRC that
           | limited protocol lines (ie. payload line + command + extra
           | fluff) to 512 bytes, so that ought to work on Discord too.
        
             | johnisgood wrote:
             | I have not yet tried, that may work since it does work for
             | IRC (which also has a limit per message). It was just more
             | of a proof of concept, tbh, but it works, just not as
             | usable as it could be.
        
           | em-bee wrote:
           | the whole point of deltachat is that it is reusing an already
           | standardized protocol with existing servers.
           | 
           | i am using element/matrix and i have tried briar. the
           | usability of deltachat and the ease of onboarding beats both
           | of those. briar was especially difficult to get started with
           | and only has a very limited usefulness compared to the
           | others. and matrix is simply very complex and easier to
           | misconfigure.
        
             | maqp wrote:
             | A standardized protocol without forward secrecy is worse
             | than standardized protocol with forward secrecy. Just use
             | Signal.
        
               | em-bee wrote:
               | forward secrecy is independent of the transport protocol.
               | it's only dependent on the encryption. messages encrypted
               | with forward secrey can still be sent over SMTP.
               | deltachat devs are working on that.
               | 
               | signal does not use a standardized protocol, and it
               | requires a phone. that's not an alternative. my children
               | have deltachat on their laptop. i can talk to them when i
               | am not at home without needing to give them a phone.
        
               | maqp wrote:
               | >messages encrypted with forward secrey can still be sent
               | over SMTP. deltachat devs are working on that.
               | 
               | OTR has had forward secrecy for 21 years. The effin
               | headline stated PGP was a faulty model
               | https://dl.acm.org/doi/10.1145/1029179.1029200
               | 
               | Why implement something PGP-like, without forward
               | secrecy, 13 years later, beats my understanding. I mean,
               | 13 years is also the time difference between OTR and PGP.
               | I guess some devs don't read cornerstone papers of the
               | field they supposedly specialize in :)
        
             | johnisgood wrote:
             | Briar had trade-offs, for example, it is not available for
             | desktop. I do not have use for Briar, personally. I use the
             | rest, but Briar is worth a mention.
        
         | JimDabell wrote:
         | > Have their been done any third-party security audits by
         | reputable companies?
         | 
         | Their FAQ answers this:
         | 
         | > Yes, multiple times. The Delta Chat project continuously
         | undergoes independent security audits and analysis
         | 
         | -- https://delta.chat/en/help#security-audits
        
         | tcfhgj wrote:
         | first of all, it's not a walled garden
        
         | em-bee wrote:
         | deltachat does not have central servers. you get to use your
         | own servers. aka it's federated. and it works with plain SMTP
         | so you can just reuse the server/email account you already
         | have.
        
           | heavyset_go wrote:
           | Delta Chat has the option of using chatmail servers that they
           | host themselves.
        
             | josephb wrote:
             | Chatmail relays can be run by anyone, they are designed to
             | be fairly minimal and lightweight, just running what is
             | needed to support the "encrypted chat" part, not regular
             | email.
        
         | singpolyma3 wrote:
         | Biggest advantages are the code is open, the infrastructure is
         | open, and you don't have to hand all your metadata to a single
         | centralized provider
        
       | blancotech wrote:
       | Anyone else immediately think of delta airlines? I was excited to
       | read an analysis of a seat-to-seat chat implementation
        
         | Bluestein wrote:
         | Like those gaggles of girls chatting each other up while
         | walking shoulder-to-shoulder down the street.-
        
         | seydor wrote:
         | seat29@flight7822.delta.com slaps seat34@flight7822.delta.com
         | with a large trout :: stop snoring
        
       | seydor wrote:
       | this is my favourite version of decentralization. building on
       | existing widely available infrastructure. The war-proof internet.
       | 
       | Maybe with AI there could be a sort of decentralized antispam
       | filtering . but maybe not
        
       | lclc wrote:
       | Has anyone used that with their Protonmail account?
       | 
       | Maybe something Proton should build on for its own chat app.
        
         | kseistrup wrote:
         | DeltaChat is incompatible with ProtonMail:
         | 
         | https://providers.delta.chat/protonmail
        
           | floren wrote:
           | They mention the bridge but if they're using pgp under the
           | hood it may well just be entirely broken:
           | https://jfloren.net/b/2023/7/7/0
        
       | b0a04gl wrote:
       | this completely sidesteps the infra bootstrapping phase. there's
       | no need for new servers, federation drama or client network lock-
       | in. every user already has a compatible backend = imap + smtp.
       | that shifts the challenge from adoption to UX. that's a very rare
       | position for a comms tool to be in. this's refreshing to me
       | personally, would love to contribute to the mission
        
       | heavyset_go wrote:
       | Note that while it might be decentralized and "secure", it is not
       | anonymizing as IMAP + SMTP are far from anonymous. Email is a
       | legacy system that was never designed with privacy or anonymity
       | in mind.
       | 
       | This is useful if you want to keep the content of your messages
       | secure, but if you need to keep your identity, social graph and
       | the fact that you conversed with certain people obfuscated, I
       | don't think Delta Chat via email is a good solution.
       | 
       | It's also only decentralized as much as public email
       | infrastructure is decentralized.
        
         | woodruffw wrote:
         | I would go a step further: this is not secure. Forward secrecy
         | and metadata privacy are table stakes in any modern secure
         | messaging design, and Delta Chat has neither.
        
           | heavyset_go wrote:
           | I agree from that perspective.
        
           | lima wrote:
           | Source: https://delta.chat/en/help#pfs
           | 
           | It's basically GPG with better UX.
        
             | newsclues wrote:
             | PGP?
        
               | __MatrixMan__ wrote:
               | GPG is gnu privacy guard, it's an open source
               | implementation of the same ideas that are PGP (pretty
               | good privacy).
        
               | singpolyma3 wrote:
               | Specifically we're supposed to call it OpenPGP these days
        
               | 47282847 wrote:
               | There is PGP, OpenPGP, and GnuPG, and they're all parts
               | of a shared ecosystem but not the same. They never were,
               | so it's not like anything changed over time about this.
        
           | em-bee wrote:
           | deltachat devs are working on forward secrecy. and as for
           | metadata, as long as the messages are sent from my personal
           | email server to the destinations email server using a TLS
           | connection, the metadata is accessible only on those two
           | servers. sure, if i use gmail then google has my social
           | graph. but so do whatsapp and telegram and others. yes, more
           | private options exist, but for example in one group of
           | friends right now the choice now is between whatsapp and
           | deltachat. whatsapp because most people in the group already
           | use it. deltachat because most people already have email.
           | signal or matrix are not under consideration.
        
             | woodruffw wrote:
             | > deltachat devs are working on forward secrecy
             | 
             | That's great, but I'm not holding my breath. PGP isn't
             | architecturally well-equipped to provide forward secrecy.
             | In the mean time, I think it's borderline negligent to put
             | this in the category of secure messaging; the world's
             | expectations for security baselines have moved on beyond
             | the mid-2000s.
             | 
             | (My reference point here is Keybase, which built a very
             | user-friendly and misuse-resistant encrypted chat on top of
             | PGP in the mid-2010s. They couldn't get to forward secrecy
             | either with PGP as their substrate.)
             | 
             | > as for metadata, as long as the messages are sent from my
             | personal email server to the destinations email server
             | using a TLS connection, the metadata is accessible only on
             | those two servers.
             | 
             | To the best of my knowledge, MTA-STS adoption rates are
             | still abysmal[1]. It's a move in the right direction, but
             | this kind of shambolic jigsaw approach to communication
             | security isn't appropriate in 2025. Sensitive messages
             | should go over protocols designed to carry them.
             | 
             | [1]: https://www.uriports.com/blog/mta-sts-survey-
             | update-2025/
        
               | em-bee wrote:
               | _PGP isn't architecturally well-equipped to provide
               | forward secrecy_
               | 
               | i have no insight into the development, but i suppose
               | that swapping out PGP for something entirely different
               | should technically be possible.
               | 
               | they did develop a peer to peer protocol with forward
               | security for real-time messages that sidesteps SMTP
               | entirely. seems a bit wierd given the premise, but the
               | devs are at least not limiting themselves to SMTP and
               | PGP.
        
               | woodruffw wrote:
               | > but i suppose that swapping out PGP for something
               | entirely different should technically be possible.
               | 
               | That would probably be good, but email is still a
               | terrible substrate for secure messaging. Clear metadata
               | is security poison; you want as little of it revealed to
               | participant servers as possible.
               | 
               | > they did develop a peer to peer protocol with forward
               | security for real-time messages that sidesteps SMTP
               | entirely.
               | 
               | That's great, but in that case: what's the value
               | proposition relative to Signal or even Matrix?
        
               | em-bee wrote:
               | the peer to peer protocol at this point is only for
               | realtime communication at which both parties have to be
               | present. like IRC, those messages are not saved. it does
               | not replace regular messaging which is stored. i was
               | merely trying to point out that the developers are
               | capable of thinking outside of the box that they started
               | from and that deltachat may develop in a different
               | direction. as someone else stated, deltachat's value is
               | that it is able to reuse existing infrastructure and does
               | not require (but allow) a new set of servers to be able
               | to work.
        
           | repeekad wrote:
           | Today I learned: table stakes is borrowed from poker
           | referring to the minimum size bet needed to participate in a
           | hand, I've heard it so many times
        
             | jeremyjh wrote:
             | That is not correct. Table stakes are not a "bet size",
             | they are the minimum you have to bring to have a seat at
             | the table. For example you might have to bring $300 to sit
             | a table where the minimum bet size (big blind) is $5. You
             | only have to bet the blinds 2 out of 10 hands (or more, if
             | short-handed), which would be much smaller.
        
               | post_below wrote:
               | As a side note, despite its popularity, Texas hold'em is
               | just one type of poker game. In most poker games (5 draw,
               | 7 stud, etc..) you ante every hand.
        
           | klabb3 wrote:
           | > Forward secrecy and metadata privacy are table stakes in
           | any modern secure messaging design
           | 
           | I think this is counter-productive, limiting the adoption of
           | meaningful security improvements. The engineering and UX
           | implications of PFS and full metadata encryption (in
           | particular social graphs) are severe. Not even signal has
           | that, and they are above and beyond for a mass consumer
           | product.
           | 
           | From the physical world, it's like saying that having
           | addresses on the letter is the same as the government opening
           | and scanning the contents of every letter. Of course I don't
           | _like_ the indiscriminate metadata collection, but there are
           | worse things.
           | 
           | If you're a spook or dissident, by all means, take extra
           | precautions. You're gonna need to anyway, in many more
           | disruptive ways than your messaging app. Personally I just
           | want to share shitposts with friends and speak freely without
           | second guessing if I'm gonna be profiled by a data broker, or
           | someone is gonna scan and store the pictures I send forever.
           | Keep in mind that the status quo (Gmail, DM on social media)
           | is incredibly bad.
        
             | woodruffw wrote:
             | I don't understand how asking for things that are bog-
             | standard is somehow counter-productive. I think the really
             | counter-productive thing here is flogging the dead horse of
             | encrypted email; ordinary people deserve better than that.
             | 
             | > Not even signal has that, and they are above and beyond
             | for a mass consumer product
             | 
             | What parts of this do you think are missing from Signal?
             | Signal has had PFS for as long as it's been called Signal,
             | and has famously minuscule metadata on users.
        
             | tptacek wrote:
             | No. Unless your messenger is at pains to make sure people
             | don't use it in life-or-death situations (for instance:
             | because they're being targeted by ICE, or the law
             | enforcement and security apparatus of their country), the
             | exact opposite thing is true.
             | 
             | These kinds of message board discussions invariably pose a
             | dilemma: "send messages in plaintext using normal email, or
             | use whatever secure messaging tool is available regardless
             | of its strength". That's false. People always have a third
             | option: _not sending the message electronically_. Most of
             | us here have messages they wouldn 't send even with their
             | most trusted messaging tools; people who are at serious
             | risk from message interception have much more dangerous
             | messages than that.
             | 
             | Recommending that at-risk people use weak secure messaging
             | as a "better than nothing" step towards real secure
             | messaging isn't just bad advice. It's malpractice.
        
             | bastawhiz wrote:
             | Metadata security isn't table stakes? I guess just pray
             | your app's UX isn't good enough that the US Secretary of
             | Defense decides to use it.
        
         | umanwizard wrote:
         | > It's also only decentralized as much as public email
         | infrastructure is decentralized.
         | 
         | So... entirely? What am I missing about your point?
        
           | binary132 wrote:
           | Public email infrastructure is almost entirely dominated by
           | Google. This is worth looking into if you're not familiar
           | with the state of affairs
        
           | heavyset_go wrote:
           | I run my own email servers, but 99% of mail goes over
           | Google/Microsoft/AWS/etc email servers anyway.
           | 
           | In practice, it's quite centralized and you're always at risk
           | of one of the big providers locking your servers out of their
           | network or putting you on a blocklist they all use.
        
         | singpolyma3 wrote:
         | It is not possible to hide the fact that you conversed with a
         | certain person from your service provider. That's part of why
         | being able to choose a service provider is so important.
        
           | heavyset_go wrote:
           | Theoretically, Cwtch[1] would afford you this obfuscation
           | assuming Tor is secure and your adversary isn't nation-state
           | level.
           | 
           | Similarly, using SimpleX private message routing via .onion
           | message relays and the fact that the system has no
           | identifiers can also afford you that obfuscation.
           | 
           | [1] https://docs.cwtch.im/
        
             | johnisgood wrote:
             | Differences between Cwtch, and SimpleX? Which are you
             | leaning towards to and why?
             | 
             | According to https://github.com/simplex-
             | chat/simplexmq/blob/stable/protoc...:
             | 
             | > identify that and when a user is using SimpleX.
             | 
             | Does this apply to Cwtch?
             | 
             | Also, is it not possible to obfsucate this traffic? Tor
             | with obfs4?
             | 
             | Related:
             | 
             | #1 - https://security.stackexchange.com/questions/241730/tr
             | affic-...
             | 
             | #2 - https://github.com/simplex-chat/simplex-
             | chat/issues/4300
             | 
             | #3 - https://github.com/tst-race/race-docs/blob/main/race-
             | channel...
        
               | heavyset_go wrote:
               | > _Which are you leaning towards to and why?_
               | 
               | Heavily sandboxed SimpleX that's firewalled to block any
               | non-Tor traffic. Chose this one because it allows for
               | offline message sending/receiving, despite privacy
               | implications, and because it has clients people will
               | actually use.
               | 
               | Cwtch doesn't let you send messages when the recipient is
               | offline by virtue of how it works, which is more secure,
               | but inconvenient.
               | 
               | When evaluating Cwtch, I think I read somewhere it might
               | send identifying metadata to your recipient, or something
               | similar, but I might just be making that up. I'll have to
               | look up what I was reading.
               | 
               | > > _identify that and when a user is using SimpleX._
               | 
               | > _Does this apply to Cwtch?_
               | 
               | With Cwtch you're running two hidden services, one on
               | either end of the chat, and that happens over Tor with no
               | middleman service, so no. A passive network observer can
               | tell when you're connecting to Tor, but you can attempt
               | to obfuscate that with transports.
        
               | johnisgood wrote:
               | > obfuscate that with transports.
               | 
               | Such as obfs4, I presume.
               | 
               | I read about RACE just now, seems interesting:
               | 
               | - https://github.com/tst-race/race-quickstart?tab=readme-
               | ov-fi...
               | 
               | - https://github.com/tst-race/race-destini
               | 
               | Have you heard about it, or have you used it before?
               | 
               | > Cwtch doesn't let you send messages when the recipient
               | is offline by virtue of how it works, which is more
               | secure, but inconvenient.
               | 
               | I agree. How much more secure is that? In the case of
               | Ricochet, this only applies to friend requests. You have
               | to be online to be able to receive friend requests, which
               | I am fine with.
        
       | maqp wrote:
       | "No, Delta Chat doesn't support Perfect Forward Secrecy (PFS).
       | This means that if your Delta Chat private decryption key is
       | leaked, and someone has collected your prior in-transit messages,
       | they will be able to decrypt and read them using the leaked
       | decryption key."
       | 
       | https://delta.chat/en/help#pfs
       | 
       | It's great they're being open about the implications. But given
       | that there's better protocols out there (Signal protocol for
       | example), it makes no sense to use inferior apps.
        
         | Valodim wrote:
         | I'm not sure that's fair. It would be if it was otherwise just
         | another messenger app, but Delta uses email as a transport,
         | which gives it a special kind of resilience. It's harder to
         | shut down email than signal.
        
           | woodruffw wrote:
           | I don't think this is true in practice. On the whole, I
           | suspect the ordinary user of email is exactly as centralized
           | as the ordinary user of Signal.
           | 
           | (The response here might be that you could run your own mail
           | server, but you've now excluded >99% of the world's
           | population from the essentially reasonable expectation of
           | secure messaging. Plus, you're then dealing with the ongoing
           | misery of securing your own mail host.)
        
             | Valodim wrote:
             | The difference is the collateral. Are you really going to
             | shut down a country's most popular local email service? Or
             | gmail?
        
               | woodruffw wrote:
               | I think the answer to that is resoundingly yes: the kinds
               | of countries that care about curtailing E2EE messaging
               | are also the ones that institute nationwide internet
               | blackouts.
               | 
               | (But also, this isn't a good argument! Repressive
               | governments love metadata, and email is an amazing source
               | of unbounded metadata even with these kinds of "secure"
               | layers slapped on top. If I was a government looking to
               | snoop on my citizens, I would _absolutely_ push them
               | towards the protocols I can infer the greatest amount of
               | behavior from.)
        
               | Valodim wrote:
               | Blocking email or gmail is much closer to a nationwide
               | internet blackout than blocking signal or tor. And even
               | repressive regimes are on a budget there.
               | 
               | I'm not sure your second point holds either - for most
               | nations, an active connection to imap.gmail.com leaks
               | little other than how actively the user uses gmail.
               | Correlating senders and receivers from that data sounds
               | technically challenging enough that I wouldn't expect
               | repressive regimes to be capable. But, to be fair, I base
               | that on nothing.
        
               | woodruffw wrote:
               | > Blocking email or gmail is much closer to a nationwide
               | internet blackout than blocking signal or tor.
               | 
               | Yes; the point was not that they're the same, but that
               | regimes that do the former tend to also do the latter.
               | Moreover, we shouldn't do insecure things because regimes
               | block the secure things; that's what the regime _wants_
               | you to do. The answer might not be Signal of Signal is
               | insufficiently decentralized, but it certainly isn't
               | email.
               | 
               | > for most nations, an active connection to
               | imap.gmail.com leaks little other than how actively the
               | user uses gmail
               | 
               | This alone is a _significantly_ larger amount of metadata
               | than schemes like Signal leak. But it also isn't true: a
               | country that controls its internet infrastructure can
               | almost certainly pull much more metadata from plaintext
               | IMAP /SMTP than just access times and addresses. And this
               | isn't hypothetical: STS is not widely adopted in the
               | email ecosystem, so plaintext downgrades are pervasive.
        
           | tcfhgj wrote:
           | you don't have to use email to federate between servers,
           | there are other protocols such as Matrix, XMPP, probably many
           | more
        
             | Valodim wrote:
             | I was not talking about federation, I was talking
             | specifically about email. It's like the domain fronting
             | feature that signal used to have, but using a service as a
             | front that is business critical.
        
           | maqp wrote:
           | "It's harder to shut down email than signal."
           | 
           | It took me two minutes to figure out DeltaChat connects to
           | the server with SNI "nine.testrun.org". Banana dictatorships
           | can trivially write firewall rules to cut those connections.
           | There are other servers, but if those are going to be usable
           | by anyone, they're going to have to be public, and writing
           | block-rules is trivial compared to spinning up new servers.
           | 
           | I'm not saying Signal is much better in this regard, I'm just
           | saying resilience isn't a useful metric to assess messenger
           | security.
        
             | em-bee wrote:
             | _DeltaChat connects to the server with SNI
             | "nine.testrun.org"_
             | 
             | sounds like a bug that can be fixed. it should not need to
             | make that connection unless you create an account on that
             | server.
        
               | maqp wrote:
               | No that's just the default behavior of connecting to
               | default server, which is what 99.9% of users are going to
               | do. You want to get rid of SNIs, you run a server
               | dedicated for DeltaChat, and then its the IP-address can
               | be blocked.
        
               | em-bee wrote:
               | _connecting to default server, which is what 99.9% of
               | users are going to do._
               | 
               | not quite. the default server feature is only a year old.
               | while deltachat itself goes back to at least 2017, so the
               | majority of users will not be on that default server now,
               | and it would be possible to offer a randomized selection
               | to prevent one default server from dominating.
        
         | em-bee wrote:
         | forward secrecy is under discussion:
         | 
         | https://support.delta.chat/t/autocrypt-key-rotation/2936
        
         | zaik wrote:
         | Modern XMPP clients implement the Signal protocol for
         | encryption and are decentralized like Delta Chat.
        
       | iqandjoke wrote:
       | Which party the developer associated with? Hopefully not CIA.
        
       | exe34 wrote:
       | Why not just create a group chat and invite FBI and Shin Bet?
        
       | monkaiju wrote:
       | Obligatory briar mention...
       | 
       | Briar supports communication over multiple mediums, including
       | wifi & Bluetooth, has forward secrecy, and feels quite 'signal-
       | like' so its not impossible to get people to use it.
       | 
       | https://briarproject.org/
        
       | kingkawn wrote:
       | Pretty Good Protection ain't good enough anymore
        
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