Hacker News Reader

> - Does WhatsApp Auto Backup encrypt messages before sending them to Google Drive or iCloud?

So you make a backup and loose the phone. What about the key? Is that gone too? Without it, encrypted backup is useless. How do you backup the key? You and me maybe will manage to do this, but what about grandma and all those people without anybody close who knows about this?

View on HN

You could backup the key like every other account password, too. Save it in your password manager, print it. Whatever. This isn't really an argument.

When Android backups Wifi passwords, those are encrypted with your Google password that Google has only a hash of. Okay, it's easily interceptable the next time you login and Google has an warrant. But still an option.

The decryption key you're talking about can be a simple password. For symmetric encryption (e.g. AES-256) even a simple password would be secure enough, while something like a 24 chars password would be unbreakable.

No, not really. Passwords are terribly low entropy, and so having a common password is not a solution, at least without using some sort of KDF or such.

Reply on news.ycombinator.com