[shmapf]

I've been wondering about this for a while.

Now both whatsapp and Facebook have this, but surely they have the encryption keys too, or how else would they seamlessly fetch your messages and decrypt them when you get a new phone?

If they do, then what's the point?

[danielschonfeld]

I don't know about either anything factual, but I believe it was said that WhatsApp crux in the e2e is the iCloud backup. I believe that's where your old message get restored from.

I believe you can also disable that iCloud backup and thus the ability to retrieve those messages with a new phone.

End-to-End means encrypted in transport and not saved (in any form that is decryptable) on their servers. To that, I believe whatsapp fulfills their end of the bargain.

[azernik]

WhatsApp for Android doesn't seamlessly fetch and decrypt messages on new installations; you have to set up Google Drive backups from your old phone, and then set up restore from those backups on your new phone.

[saint_fiasco]

Last time I switched phones, Whatsapp did not restore my old message history. Facebook did, but that was before E2E.