Until now, WhatsApp relied on your phone’s contact book to sync contacts. If a new person messaged you on the app, and you wanted to save their details, the information would be stored locally on your device.
The new feature, rolling out soon, lets you store contacts on any device, including WhatsApp for the web and Windows. You can choose to sync contacts saved within WhatsApp to your phone, as well.
Last year, the company began allowing users to log into two WhatsApp accounts on one device. Saving contacts linked to one WhatsApp account is handy if you want to keep personal and business contacts separate. Plus, if you share the device with others, you can maintain your own contact list linked to your number.
WhatsApp said it developed a new encrypted storage system called Identity Proof Linked Storage (IPLS) to enable secure contact saving. When users save a contact, the system generates an encryption key on the device. The retrieval is based on the client authenticating its primary device identity.
Additionally, the app is partnering with Cloudflare to sign any changes to the cryptographic properties of a user’s directory. According to Meta, this step ensures that someone has not edited contacts saved in WhatsApp.
The company said that the tech behind the contact storing feature would make it possible to save contacts by usernames.
“Usernames on WhatsApp will add an extra degree of privacy so that you don’t need to share your phone number when messaging someone,” the company noted in a blog post.
The feature has been in development for some time. In May 2023, a report by WABetaInfo highlighted that WhatsApp has been working on introducing usernames to the app.
