How WhatsApp enables multi-device capability

My phone having recently died, I&#x27;ve recently discovered a number of very annoying limitation to WhatsApp that are making me question my use of it:<p>1. It&#x27;s impossible to export your chat history, except for one conversation at a time. The only exception to this is if you root an android phone which gives you access to the raw database.<p>2. It&#x27;s impossible to move chat history from an android device to an iOS device. And moving from ios to android is only possible with certain samsung phones.<p>3. It&#x27;s impossible to access WhatsApp from more than one phone at once. This is mostly still true with this update. You cannot use the mobile app as a &quot;companion device&quot;.<p>Do people not consider their chat histories valuable? I have my SMS history going back to 2011 (when I first got an android phone). Email can be archived. Facebook messenger keeps messages in perpetuity. WhatsApp is a frustrating outlier here.

This feature (or lack thereof) is pretty much my biggest gripe against Signal. I still don&#x27;t understand why they won&#x27;t let you use the same account in paralel on an Android tablet. And the weird part is they provide no explanation for this limitation while this limitation does not exist for iPad users.<p>If this new feature proves to work as advertised, I might as well sell my soul to the Facebook devil and go back to WhatsApp full time due to how frictionless the experience is (and everyone in the EU already being on it), and leave Signal only for private info sharing, as I grew tired of convincing people in my circles to move to Signal for privacy only to receive complaints that X,Y, Z features from WhatsApp are either missing, buggy or super frustrating to use on Signal. Oh, and receiving calls on Signal for Android is a mess (known bugs for years) where some calls just won&#x27;t come through to my phone even if the desktop client is ringing, only to have it show up as a missed call notification on my phone a few minutes later. Unacceptable.<p>I do support the Signal team for their work and what they stand for, but my patience (and that of those around me I convinced to switch from WhatsApp) is wearing thin.

Let&#x27;s remind ourselves of a few facts:<p>Facebook takes part in the US government&#x27;s mass surveillance operations, granting wide, possibly complete, access to users&#x27; communications. This was revealed by whistle-blower Edward Snowden and the documents he had released. Facebook&#x27;s interaction with the NSA or other government agencies is kept secret, and will not be admitted, so when Facebook tells you your communications via its applications and services are secure, that is certainly not wholly the case, and quite possibly not at all the case.<p>Additionally, Facebook uses your communications for its own business interests, e.g. to manipulate you into paying for services or products whose providers pay Facebook, or for other kinds of social engineering. It stands to reason that this includes the information Facebook gathers about you from your WhatsApp conversations.<p>There are other messaging applications with multi-device capabilities - better or worse - and we should strive to use those with open source code, well-established algorithms, and transparent, robust and trustworthy governance as projects.<p>----<p>So - please do not use WhatsApp and try to get your friends and family to switch to alternative applications. Signal and Telegram seem to be the popular alternatives, even if they each have their own shortcomings and flaws.

Something that is interesting here is on-boarding new devices. Since all the encryption is done by each message being sent to the {all sender devices (M), all receiver devices (N)} you end up with M+N encryptions.<p>When onboarding a new device, it needs some amount of state in order for conversations to have a useful context. So the new sender device gets a bundle of recent conversations from who-ever onboarding it. I&#x27;m not clear on how you could control the amount of context or add more state, but that is off-topic.<p>What I&#x27;m wondering is: Does this have a race condition? Say that you have:<p>Sender A knows about receivers {B,C,D} Sender A sends message Foo to {B,C,D} Receiver E is onboarded at the same time Foo is sent. Is there no state where E does not receive the message?<p>I&#x27;m sure that this is accounted for and out of scope in a high level blog post, but I am curious how that part works.

Hopefully this will make using the WhatsApp bridge on Matrix much easier - one of the reasons I haven&#x27;t gone all in on Matrix. If I can have a device setup that is linked, then I don&#x27;t have to run a VM or (hopefully) have it even installed on my phone.

The ship has sailed. While we endure incessant &#x27;we want you to bend backwards and agree to our new TOS&#x27; in WhatsApp, Telegram keeps being friggin&#x27; awesome and getting better every fortnight or so.

Perhaps this is an odd question - but can someone comment on why this was posted today? The blog post is from July, so I&#x27;m wondering whether it&#x27;s past the initial experimentation phase or something?

ctrl+F &quot;XMPP&quot;… No? OKay, I&#x27;ll be that guy.<p>Multiple devices, multiple platforms, E2EE, gateways to other networks... my XMPP server handles all of that, and I convinced non-tech users to use it mainly because of the great Android client Conversations.<p>Yes, there are some rough edges because there isn&#x27;t a iOS client that matches Conversations in terms of user friendliness. But siskin-im in on its way there.<p>I also have had complaints from friends but mainly because I am a shitty admin...<p>Oh, and having your phone number as your username is something that really is important for you? Use Quicksy then.

Can anyone with good knowledge of the protocol explain the differences between what WhatsApp is rolling out now and what Signal has been doing for a long time now?

Does anyone with knowledge on the subject know how different it is from what Matrix&#x2F;Element does? or any other implementation?

End-to-end encryption on multi-device? I think Matrix and Element solved this before.

&gt; With this new capability, you can now use WhatsApp on your phone and up to four other nonphone devices simultaneously — even if your phone battery is dead.<p>Does &quot;non-phone&quot; here at least include &quot;iPad&quot;? The use case of &quot;if your phone battery is dead&quot; is just such a non-issue for me, as I have a million other critical reasons to keep my phone charged and online... but having the WhatsApp external client--the one you install on laptops--available for iPads and even other phones would actually open up new use cases for me.

Whitepaper: <a href="https:&#x2F;&#x2F;web.archive.org&#x2F;web&#x2F;20210922105222&#x2F;https:&#x2F;&#x2F;www.whatsapp.com&#x2F;security&#x2F;WhatsApp_Security_Whitepaper_v4_Preview.pdf" rel="nofollow">https:&#x2F;&#x2F;web.archive.org&#x2F;web&#x2F;20210922105222&#x2F;https:&#x2F;&#x2F;www.whats...</a>

With more and more services going e2e encrypted, the application servers no longer have any special role or logic. All data they store is no longer privacy or security critical, and they no longer need ACL&#x27;s.<p>I&#x27;d therefore like to see future chat services like this to just have one big S3 backend (or similar).

Now if they&#x27;d just stop the spam and get rid of the phone numbers! There is ZERO good reason to require a phone number in 2021 nor to access my contact list of which the majority fo the people I talk do I don&#x27;t have their number.

It has been a while.<p>Also now, when a conversation is archived it remains archived even if someone in that group posts something. Before when someone in an archived conversation posted something the conversation would be unarchived.

Crazy that an application is proud, in 2021, to be usable on multiple devices.

That&#x27;s an interesting and long awaited update. But there&#x27;s no mention of a new desktop app, or new web app. I wonder how users in the beta will be able to test this.

I could run chat programs on multiple computers in the 90s, so today we&#x27;re in a worse state than then. What gives?

But only one phone, yeah...

Smells of NSA.

Don&#x27;t worry, we will store those keys nice and safe.... In case we get subpoenaed. Just scan you retina.

WhatsApp uses the Signal encryption subsystem and they only allow one other machine.<p>What is FB doing that allows this on Whatsapp but not Signal.<p>What a WhatsApp users opening themselves up for here?