Facebook CEO Mark Zuckerberg made the announcement with a Facebook post, saying the end-to-end encryption option will store your backup messages in either Google Drive or iCloud. “WhatsApp is the first global messaging service at this scale to offer end-to-end encrypted messaging and backups, and getting there was a really hard technical challenge that required an entirely new framework for key storage and cloud storage across operating systems,” Zuckerberg wrote on his Facebook post. A whitepaper detailing the new feature published on Friday notes that WhatsApp users will have to save a 64-digit encryption key or make a password when saving their encrypted backup messages. In addition, end-to-end encrypted backups will only be supported on a user’s device. “Once the end-to-end encrypted backups feature is enabled in the WhatsApp application, the client uses a built-in cryptographically secure pseudorandom number generator to generate a unique encryption key K,” the whitepaper details. “The cryptographic strength of K in terms of length is 256 bits, i.e., 32 bytes. That key K is only known to the client and is never transmitted outside of the client unencrypted.” The Verge notes that WhatsApp’s announcement puts its encryption capabilities ahead of Apple’s. While Apple has end-to-end encryption of its iMessages, it does not encrypt backup messages, even though it initially had plans to do so. Aside from encrypting your backup messages, WhatsApp also is developing a way to hide your active status from specific contacts. These would be new privacy tools that give you more control over who sees your status; you can choose “Everyone,” “Nobody,” “My Contacts,” and now, “My Contacts Except” for your Last Seen.
