Signal has taken a proactive step in enhancing user privacy with the latest update to its Windows application. The introduction of a feature known as “screen security” aims to thwart Microsoft’s AI-driven Recall functionality, which has raised significant privacy concerns since its launch.
Enhancing Privacy with Screen Security
By default, screen security is now active on all Windows 11 devices. Recall, which continuously captures screenshots of all active windows at regular intervals, analyzes this data to create a searchable database using natural language processing. In response to the potential risks associated with this feature, Signal’s screen security sets a Digital Rights Management (DRM) flag on its app windows. This effectively prevents Recall and other Windows applications from capturing any content displayed within Signal.
The introduction of Recall in May 2024 sparked alarm among security experts, who labeled it a “privacy nightmare” and a considerable security risk. The concern was that malicious actors could exploit this feature to harvest sensitive user data. In light of these criticisms, Microsoft has since made Recall an optional feature, requiring users to authenticate via Windows Hello. Additionally, updates have been made to filter out sensitive information and exclude certain applications and private browsing sessions from being captured.
David Weston, Microsoft’s VP for Enterprise and OS Security, noted in September that enhancements to Recall included rate-limiting and anti-hammering protections against malware, as well as options for users to manage storage settings and delete snapshots. However, despite these improvements, Signal’s developer Joshua Lund expressed ongoing concerns about the risks posed to content displayed within privacy-focused applications like Signal.
In a recent blog post, Lund emphasized the necessity of implementing this additional layer of protection on Windows 11, acknowledging that it may come with usability trade-offs. “Microsoft has simply given us no other option,” he stated. Users who wish to disable screen security can do so through Signal’s settings, but they will receive a warning that disabling this feature may expose their chats to potential screenshots by Windows.
Lund further articulated the challenges faced by applications like Signal, which have limited control over what Recall can capture. He urged AI developers to consider the implications of their technologies more thoroughly, advocating for a balance between privacy and accessibility. “People who care about privacy shouldn’t be forced to sacrifice accessibility upon the altar of AI aspirations,” he remarked.
It is important to note that while enabling Signal’s screen security on Windows devices offers some protection, it does not safeguard against screenshots or recordings made by users employing screen readers on macOS or Linux systems.
As of April, Microsoft began rolling out Windows Recall to all users who installed the Windows 11 KB5055627 update on Copilot+ PCs, making it generally available to all users with the May 2025 Patch Tuesday updates shortly thereafter.
