“Starting today, we are making available an extra, optional layer of security to protect backups stored on Google Drive or iCloud with end-to-end encryption,” the company said in a blog post.
“No other global messaging service at this scale provides this level of security for their users’ messages, media, voice messages, video calls and chat backups.” Users will have a choice for how the encryption key used is stored. The simplest is for users to keep a record of the random 64-digit key themselves, akin to how Signal handles backups, which they would need to re-enter to restore a backup.
The alternative would be for the random key to be stored in WhatsApp’s infrastructure, dubbed as a hardware security module-based Backup Key Vault that would be accessible via a user-created password. For redundancy purposes, WhatsApp said the key would be distributed through multiple data centres that operate on a consensus model. WhatsApp said it would only know that a key exists in its vault, but would not know the key itself.
The backups would store message text, as well as photos and videos received, WhatsApp said.

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