[HN Gopher] How WhatsApp is enabling end-to-end encrypted backups
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       How WhatsApp is enabling end-to-end encrypted backups
        
       Author : baby
       Score  : 37 points
       Date   : 2021-09-10 16:41 UTC (6 hours ago)
        
 (HTM) web link (engineering.fb.com)
 (TXT) w3m dump (engineering.fb.com)
        
       | Retric wrote:
       | The option to use a private encryption key is presumably useful,
       | though their still storing logs unencrypted on the users device.
       | 
       | The password option is not really what I would call end-to-end
       | encrypted. This is only as secure as a dictionary attack on users
       | passwords so in practice it looks to be trivially crackable
       | should the FBI etc get a copy of the users "encrypted" data in
       | the key vault + their logs from the cloud storage provider.
       | 
       | https://eprint.iacr.org/2018/163.pdf
        
       | vinay427 wrote:
       | This is great to see, particularly as WhatsApp currently handles
       | this entirely incompetently despite claiming that the feature
       | exists, providing no accurate or sane documentation about local
       | backups. I recently had the issue for the second time of losing
       | over a year of messages due to dysfunctional WhatsApp backups,
       | about which I wrote a blog post of complaints/rants [1].
       | 
       | The user, as far as I can tell at least on Android, currently has
       | no viable option besides uploading their messages, unencrypted,
       | to Google.
       | 
       | [1] https://vinayh.com/posts/2021-08-28/
        
         | ars wrote:
         | I hate WhatsApp, it has a habit of losing messages. And
         | transferring WhatsApp to a new phone is almost impossible to do
         | without losing some messages EVEN if your current phone still
         | works.
         | 
         | You have to hit the backup button, and hope it finishes and
         | sends everything to Google before you get a new messages from
         | anyone. If you do get a messages, press backup and try again
         | (or just lose that message).
         | 
         | Recently I had the misfortune of trying to transfer WhatsApp
         | from a phone that took 22 hours to finish each backup - so
         | there was no other option except lose messages.
         | 
         | And if your phone is dead, you are all but guaranteed to lose
         | messages, since it uses the last backup.
         | 
         | It gets worse - if you delete photos from your WhatsApp
         | storage, WhatsApp does not delete them from the Google backup.
         | If you do this for long enough you can end up with a Google
         | backup too large to restore to any phone (or at least too large
         | to fit in your current phone - I guess you could buy a 256GB
         | model).
         | 
         | You have to delete the Google backup every once in a while, and
         | then quickly backup again (which takes hours or days, since it
         | has to re-upload every single photo and video you have).
         | 
         | All WhatsApp needs to do to fix this is: a: continuous backups
         | - you get a message, it saves that message to google, or b:
         | save at least 1 month worth of old messages, so that it has
         | them in case you need to restore from an old backup. (It could
         | prune old message every time you finish a backup.)
         | 
         | And don't get me started on the misery that is losing your
         | phone, or it breaks, and you are without a phone for a little
         | while - you have zero options of getting messages. At least
         | with SMS you could put the SIM card in a loaner phone, but
         | WhatsApp probably won't fit in some cheap phone without much
         | storage.
         | 
         | I hate WhatsApp with a passion, and I wish it didn't exist -
         | but I have no choice but to use it, since all my contacts don't
         | even seem to understand what a regular text even is.
         | 
         | And I can guarantee that this encrypted backup with cause lots
         | and lots of people to lose their messages.
        
       | leonixyz wrote:
       | This is ridicolous, they block the account of people for no
       | reason, making them loose years of messages, and now they come up
       | with encrypted backups... they should focus on improving their
       | support. They have only an email address for support. Try to get
       | your account unblocked if their AI decides to block you. Good
       | luck
        
       | baby wrote:
       | Whitepaper:
       | https://scontent.whatsapp.net/v/t39.8562-34/241394876_546674...
       | 
       | I think this is similar to how Google encrypts your backups.
        
       | monocasa wrote:
       | Discussion of the whitepaper here:
       | 
       | https://news.ycombinator.com/item?id=28484681
        
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       (page generated 2021-09-10 23:02 UTC)