In a move that's set to revolutionize the way users interact with the popular messaging app, WhatsApp has announced a new feature that allows users to save contacts within the app itself. This means that even if you lose your phone or switch to a new device, your contacts will be safely stored in WhatsApp's cloud storage, accessible across all devices, including WhatsApp for web and Windows.

The new feature, which is rolling out soon, marks a significant departure from WhatsApp's previous reliance on phone contact books to sync contacts. This update will enable users to maintain separate contact lists for personal and business use, and even share devices with others while keeping their contact information private.

WhatsApp has developed a new encrypted storage system, Identity Proof Linked Storage (IPLS), to ensure secure contact saving. The system generates an encryption key on the device, and retrieval is based on client authentication of primary device identity. Additionally, WhatsApp is partnering with Cloudflare to sign any changes to the cryptographic properties of a user's directory, preventing unauthorized edits.

The tech behind this feature also paves the way for saving contacts by usernames, adding an extra layer of privacy and allowing users to share their username instead of their phone number. This move brings WhatsApp in line with rivals Signal and Telegram, which already offer username-based sharing.