End-to-end encryption isn’t a new feature to WhatsApp as the feature was enabled back in 2016. However according to recent reports, WhatsApp has quietly introduced encryption to its iPhone chat backups whenever they are uploaded to iCloud, making it quite a huge change from the previous backup process.
Prior to this, WhatsApp stored iPhone chat backups on iCloud in a readable form. It should be noted that iCloud backups are encrypted, but should someone like a hacker or law enforcement gain access to Apple’s decryption key, they’d be able to access the user’s entire communication history.
With WhatsApp enabling encryption for chat backups in iCloud, this means that even if someone were to get their hands on the decryption key for iCloud, your WhatsApp chat backups will still be safe. Of course if WhatsApp’s encryption key is stolen or given to law enforcement, that would be an entirely different story, but for now it will act as a second layer of security.
According to WhatsApp, “When a user backs up their chats through WhatsApp to iCloud, the backup files are sent encrypted.” Unfortunately it is unclear if this encryption has been extended to Android users, but presumably it has or eventually will.