Signal tests feature allowing users to keep their phone number undisclosed

Username to be the primary contact method

Signal is in the process of public testing for a username feature that would allow users to communicate without sharing their phone numbers. This feature is still in the pre-beta phase and has been announced by Jim O'Leary, Signal's VP of Engineering. Users are advised of potential rough edges during this phase, including possible crashes and notification issues, with an official release aimed for early 2024.^[1]

The move to allow usernames addresses a privacy concern by enabling users to avoid sharing their phone numbers—a sensitive personal identifier. Although Signal will still require a phone number for account setup, the username feature will permit contact without revealing this number.

The feature's design also includes the ability to set the username as the primary contact method, with provisions to prevent phone number sharing through user profiles. Signal has been developing this privacy feature for some time, with early indications dating back to 2019.^[2]

The first news about the feature came from cybersecurity specialist Lukasz Olejnik, Ph.D, LL.M, who announced it on Twitter/X:^[3]

Signal is testing username feature. This would mean that you would not have to provide your phone number to people you want to contact. You will be able to set your phone number as private and not share it.

QR codes or links can be used instead of the phone number

Signal's testing of this feature involves a staging environment, a separate instance from the stable version of the app, where users can test new functionalities. This setup necessitates the installation of test builds and registration for a new account, which can be done with the same phone number used in the main app.

Signal has provided guidelines for users to test features such as creating usernames, sharing them via QR code or link, and managing phone number discovery settings. Signal's VP of Engineering, Jim O'Leary, explained it's easy to enable the Beta feature:^[4]

Once you’re registered and running the app, please navigate into Settings / Profile and Settings / Privacy / Phone Number to explore the new functionality available in these builds. Please test creating usernames, sharing username links, modifying the sharing settings for your phone number, and inviting people to groups by username and by phone number alike.

However, these builds are part of an early pre-release stage and may undergo daily updates, emphasizing their impermanence.

The introduction of usernames by Signal coincides with privacy enhancements by other messaging services like WhatsApp.^[5] However, Signal has been more transparent about its plans compared to its competitors. The username feature, while enhancing privacy, may also introduce risks, including the potential for user impersonation. This concern reflects the broader industry challenge of balancing user privacy with platform integrity and safety.

User participation in pre-beta testing

Signal encourages user participation in the pre-beta testing phase, which is available across platforms, including Android, Desktop, and iOS. The ease of installing these test clients varies, with detailed instructions provided for each platform.

Signal's community forum offers resources for users to install macOS and Windows desktop installers, and Linux users can access the build through the Desktop Alpha apt repository. For iOS, while there is no staging build available via the App Store, users can compile their own Signal-Staging iOS app using the provided source code.

Signal's development team has highlighted the importance of understanding the nature of pre-beta testing, where data may not be preserved, and users may need to reinstall the app to resolve issues.

With a cautious rollout and community testing, Signal is addressing the need for privacy in digital communication while also navigating the challenges that come with introducing new features. The potential for increased user privacy through usernames is balanced with clear communication of the feature's current limitations and the broader context of its development.