WhatsApp gets private contact management across devices


WhatsApp has announced significant updates to how users can add and manage contacts, making it easier to do so from any device. The company stated that these changes aim to help users “privately add and manage” their contacts on WhatsApp.

Previously, users could only add contacts through their mobile devices by typing in a phone number or scanning a QR code. Soon, it will be possible to manage contacts directly through WhatsApp Web and Windows, with plans to extend this feature to other linked devices.

Add and manage contacts across devices

Additionally, WhatsApp introduced an option to save a contact exclusively to WhatsApp, beneficial in several scenarios:

  • Sharing a phone with others
  • Managing both work and personal WhatsApp accounts on one device
  • Restoring contacts when losing a phone or changing devices

Contacts saved solely on WhatsApp will be recoverable if a device is lost or changed. WhatsApp plans to allow management and saving of contacts by usernames in the future, enhancing privacy by eliminating the need to share phone numbers when messaging.

Identity Proof Linked Storage (IPLS)

Identity Proof Linked Storage (IPLS) is a new encrypted storage system introduced by WhatsApp for contact management.

It enables users to create contacts within WhatsApp and choose to sync them to their phone or save them solely to WhatsApp. This allows seamless contact management across linked devices, and users can customize their contact lists for multiple accounts on the same device.

Contact names will be stored encrypted within WhatsApp, using IPLS to protect user privacy. WhatsApp has partnered with Cloudflare for third-party audits of IPLS’s cryptographic security. This ensures that contact lists are securely managed and protected from unauthorized access.

Key Features of IPLS:

  • Encrypted Storage: Users’ contact names are encrypted and stored securely, retrievable only through authenticated client devices.
  • Privacy Technology: The system safeguards contact lists while allowing users to verify their identities cryptographically.
  • Third-party Auditing: Cloudflare helps ensure the integrity of IPLS with independent validation of changes.

The IPLS infrastructure relies on WhatsApp’s existing technologies, such as key transparency and hardware security modules (HSM), to enhance security and privacy. It allows users to manage their contacts effectively without losing them during device changes or application reinstalls.

Availability

These features will be rolled out gradually over the coming weeks and months.