[HN Gopher] Apple will soon support encrypted RCS messaging with...
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Apple will soon support encrypted RCS messaging with Android users
Author : 01-_-
Score : 64 points
Date : 2025-03-14 12:07 UTC (10 hours ago)
(HTM) web link (www.theverge.com)
(TXT) w3m dump (www.theverge.com)
| thomascountz wrote:
| Announcement discussion from 2023:
|
| Apple announces that RCS support is coming to iPhone next year
|
| https://news.ycombinator.com/item?id=38293082
|
| 793 points | 709 comments
| pityJuke wrote:
| To be clear, this is a different announcement. That was just
| RCS, this is encrypted RCS.
| cantSpellSober wrote:
| The big difference:
|
| > _The GSM Association announced that the latest RCS standard
| includes E2EE_
|
| > _While Apple's proprietary iMessage system already supported
| E2EE, this wasn't extended to RCS messaging because the
| previous RCS standard didn't provide cross-platform support_
| criddell wrote:
| When an iPhone sends a message to 555-1212, where does the iPhone
| get the public key for that number?
| acdha wrote:
| Apple runs servers for managing iMessage key exchange, just
| like Google's RCS encryption. Both of them use device
| attestation to restrict access to those servers to their own
| apps.
| oneplane wrote:
| So essentially, it's not really an Apple thing, it's more that
| the universal RCS profile just didn't have encryption, and Google
| RCS was a non-standard extension that nobody else was allowed to
| use.
|
| The real news is the update to GSMA RCS, because without that,
| none of this matters. What I'm missing in the article is who's
| going to own the keys and why this is probably going to default
| to the telcos as if it's MMS. Are they going back to the days of
| charging per message?
|
| With iMessage you'd be putting your trust in Apple, with Google
| RCS you'd be putting your trust in Google. For WhatsApp that'd be
| Meta and for Signal that's Signal. But with GSMA RCS?
| she46BiOmUerPVj wrote:
| Is there anything that shows "no one was allowed to use it" or
| was it that it wasn't an accepted standard?
| oneplane wrote:
| Yes, Google only made it available for Google Messages. They
| don't have an SDK or API you can use to make your own clients
| or servers. Google also didn't put it up for standards with
| the GSMA or any other standards body, at least not publicly.
| There are no records of it.
|
| There are some older submissions here you can probably find
| using one of the HN search sites about this, but IIRC those
| didn't really have any internal Google policy about this,
| they kept it all pretty private. The only 'leak' I remember
| about this was the thing where manufacturers that preload
| Google Android have to ship Google Messages to get RCS
| support from Google, otherwise they can't have it. Also means
| you can't have RCS without Play Services.
| jauntywundrkind wrote:
| The destruction of third party apps has been totally wild.
|
| I'm very curious how long this OS-coupled status quo is
| going to go on for.
| acdha wrote:
| Look at Google's documentation: they explicitly state that
| only their Messages app is allowed to talk to their key
| exchange server. The entire marketing campaign they ran about
| RCS was predicated on nobody reading their docs or noticing
| all of the Android developers begging for permission to use
| RCS for years.
|
| https://www.gstatic.com/messages/papers/messages_e2ee.pdf
|
| > E2EE is implemented in the Messages client, so both clients
| in a conversation must use Messages, otherwise the
| conversation becomes unencrypted RCS. In rare situations
| where the conversation starts as E2EE, then one of the
| clients migrates to a different RCS client or an older
| Messages client that does not support E2EE, Messages might be
| unable to detect the change immediately. If the Messages user
| sends a new message, it's still E2EE, however the recipient
| client may render the encrypted base64 payload directly as
| message content.
| stephenr wrote:
| I understand your point that the "news" part is that RCS
| standard now includes E2EE, rather than about Apple's support
| for said standard.
|
| But I don't think it's fair to suggest or imply that this
| development is unrelated to Apple either.
|
| RCS has been a thing for nearly a decade, and _Google_ 's RCS
| backend has been doing non-standard E2EE for half that time.
|
| Within 8 months of Apple publicly announcing they would adopt
| RCS and work with GSMA to support _standardised_ E2EE, there is
| suddenly a standard for it...
| jeroenhd wrote:
| The encryption is based on MLS: https://www.rfc-
| editor.org/rfc/rfc9420.html
|
| I don't think Google wanted to gatekeep their E2EE
| implementation. They have some generic documentation about how
| it works:
| https://www.gstatic.com/messages/papers/messages_e2ee.pdf
|
| The thing about RCS is that no messengers seem to care at all
| about implementing RCS themselves. Part of that is probably
| because depending on the carrier, RCS may require access to
| certain SIM card information, which only pre-installed apps can
| do, and part of it is that many developers are waiting for
| Google to add RCS to the same API that SMS/MMS already exposes
| because they don't want to implement RCS themselves.
|
| Realistically, the target demographic for their documentation
| is 1) Apple (who they'd happily supply with details to get rid
| of the green bubble problem) and maybe 2) government officials
| looking into antitrust concerns. In theory someone working for
| LineageOS can implement an RCS client, though, but for those
| developers I don't think reverse engineering the remaining
| unknowns about the protocol (mostly "what server" and "what
| message contents") aren't that difficult.
|
| I'm not cryptographer, but I haven't heard any major issues
| from actual cryptographers about MLS. It's encryption
| principles seem to be similar to those of Signal. Google is
| actually already using MLS in their proprietary E2EE
| implementation.
|
| Ideally, MLS would be combined with MIMI so that messaging apps
| become interoperable, but that's probably a pipe dream.
| acdha wrote:
| The protocol is open but key exchange is not: even on
| Android, third-party messengers can't interoperate with
| Google Messages. See page 11 of that PDF.
| mrweasel wrote:
| Why was RCS even designed with a none encrypted mode? I get that
| the original spec isn't exactly new, but it's also not so old
| that encryption, security or privacy wasn't an issue.
| nubinetwork wrote:
| I'm not sure about the case of RCS, but I've seen some
| instances of a none cipher being better for compression and
| deduplication, because the encryption messes with the data.
| hagbard_c wrote:
| You'd normally compress the data before encrypting it as that
| makes the resulting cyphertext more resilient against
| cryptanalysis as well as reduces the amount of data which
| needs to be encrypted so this sounds like a bogus reason.
| nubinetwork wrote:
| It depends on what you're doing I guess... for storage it
| doesn't make sense, but for pushing a lot of data over a
| private pipe, why spend the resources adding a cipher?
| jayd16 wrote:
| You'd have to compress every single message separately and
| then encrypt them. That's still a far cry from being able
| to compress across every message.
| dontlaugh wrote:
| I assume some sort of multicast.
| jeroenhd wrote:
| It's the evolution of SMS/MMS; development started 18 years
| ago, in 2007. The modern spec is based on that with a whole
| bunch of additional revisions for things like video calling and
| transferring money. It was designed long before major messenger
| apps had e2ee in the first place.
|
| Had it been designed with the security practices at the time,
| the protocol would've been ossified to the point of being
| practically insecure by today's standards. In a sense, the fact
| nobody cared about it until the spec was old enough to drive is
| actually good for users.
|
| The GSMA which designs RCS also serves the needs of government
| agencies that are tracking (international) criminals, so I bet
| there must have been some pretty strong opposition against E2EE
| in the official spec. Frankly, I'm surprised they're even
| putting it in the spec.
| izacus wrote:
| Encryption and privacy isn't an issue for carriers, which were
| part of the standard body and operate SMS protocol even in
| 2025.
|
| You assume everyone has the same goals in mind :)
| snowwrestler wrote:
| Now if only we could get Google to support RCS in Google Voice.
| toomuchtodo wrote:
| It's really odd they don't, I'm incredibly curious why.
| chneu wrote:
| GVoice gets forgotten about, I swear.
|
| There are years between updates and then suddenly for like 6
| months it'll get a slew of updates, most of which aren't
| user-facing. Then back to update silence. It's really odd.
|
| I'm still amazed that google hasn't killed it.
| the-rc wrote:
| I always wondered if it's still alive only because Larry or
| Sergey use it every day.
| codedokode wrote:
| It is good that commercial messengers forced GSM association to
| finally create E2EE standards. The reason why telcos want you to
| use RCS becomes obvious if you calculate how much 1Gb of data
| costs if sent as SMS (I guess that one could buy a car with this
| money).
| qrush wrote:
| Still waiting for Google Fi to turn RCS on for iOS users :(
| bilal4hmed wrote:
| its coming
|
| https://9to5google.com/2025/03/04/google-fi-rcs-ios-18-4/
| ebb_earl_co wrote:
| This is great in principle. I still prefer Signal as the top-
| shelf experience of iOS--Android communication.
| tengbretson wrote:
| Still waiting on a non-Google implementation of this so-called
| standard.
| WorldPeas wrote:
| Any news on if/when one will be able to send RCS from a program
| or device outside the monolith?
| bebna wrote:
| Never. It is just a fancy MMS in new disguise. Carriers /
| patent holders will hold to it forever while praising it as the
| new best thing.
| singpolyma3 wrote:
| You can get access to send MMS though. RCS there is no one
| selling access yet, especially for person to person.
| alwayslikethis wrote:
| Unfortunately, RCS on Android requires google apps, so this isn't
| really a solution to anyone who doesn't want to be tracked by
| Google everywhere they go.
|
| I'm still a little confused as to what problem RCS is supposed to
| solve. It is just as centralized as any other chat app, and is a
| bit more invasive (often requiring device attestation). Is it
| really worth all this hassle just to not have to install, let's
| say, Signal?
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(page generated 2025-03-14 23:01 UTC)