Microsoft has made changes to Recall – the screenshot-taking, AI-powered search feature for Copilot+ PCs running Windows 11 – to reassure users worried about security and privacy.
The security of the feature has been assessed by Microsoft’s Offensive Research & Security Engineering team and by a third-party security vendor, Microsoft says. Other security professionals will hopefully probe the feature for weaknesses that could put user data at risk.
Welcome changes
Microsoft unveiled the Copilot+ Recall feature in May 2024, and it didn’t take long for security and privacy-minded researchers to point out its many security pitfalls and worry about it opening the door for malware and unauthorized users to easily grab sensitive data.
Microsoft reacted by pausing the release of the feature and announcing crucial changes.
On Friday, David Weston, VP of Enterprise and OS Security at Microsoft, confirmed that Recall will be an opt-in experience from the start, and that users will be able to remove it via the optional features settings.
Snapshots and any associated information will be encrypted and the encryption keys protected via the Trusted Platform Module (TPM), tied to a user’s Windows Hello Enhanced Sign-in Security identity.
“Within Recall, the services that operate on screenshots and associated data or perform decryption operations reside within a secure VBS Enclave. The only information that leaves the VBS Enclave is what is requested by the user when actively using Recall,” he pointed out.
Access to the feature and its user interface is protected via Windows Hello, which allows users to sign in via biometrics (face or fingerprint) or PIN. “Biometric credentials must be enrolled to search Recall content. Recall currently supports PIN as a fallback method only after Recall is configured, and this is to avoid data loss if a secure sensor is damaged,” Weston added.
“Authorization will time-out and require the user to authorize access for future sessions. This restricts attempts by latent malware trying to ‘ride along’ with a user authentication to steal data.”
Recall security arhitecture (Source: Microsoft)
Microsoft has also added rate-limiting and anti-hammering measures to protect the information stored by Recall from brute-force attacks.
Finally, Recall will not save information from private browsing sessions on Microsoft Edge, Firefox, Opera, Chrome, and Chromium based browsers, and sensitive content filtering – which should help reduce passwords, national ID numbers and credit card numbers from being stored in Recall – will be on by default.