Windows 11 Insider Preview Build 27863 Introduces Post-Quantum Cryptography and Key Stability Fixes

Windows 11 Insider Preview Build 27863 is now available in the Canary Channel, introducing post-quantum cryptography support and critical fixes for Windows Sandbox, safe mode, and language-specific crashes. Known issues remain, but ongoing improvements promise a smoother experience. :

Windows 11 Insider Preview Build 27863: What’s New in the Canary Channel

Microsoft just dropped Windows 11 Insider Preview Build 27863 for the Canary Channel. This release brings exciting updates, especially in security and cryptography. If you’re a Windows Insider who loves testing new features early, this build is worth checking out.

Post-Quantum Cryptography Support

One of the biggest highlights is the addition of post-quantum signature algorithm ML-DSA support. This update integrates ML-DSA into NCrypt, BCrypt cryptography APIs, and Crypt32 certificate APIs. Three variants—ML-DSA 44, 65, and 87—are now supported.

“We encourage you to try out using and validating ML-DSA certificates with these changes.”

This move aligns with Microsoft’s push for stronger, quantum-resistant security measures, announced recently at the Build conference. Developers and security pros should definitely experiment with these new cryptographic options.

Important Fixes You Should Know

Build 27863 also addresses several bugs that were causing headaches in previous versions. For example, Windows Sandbox now launches without the error 0xc0370106. Core Windows surfaces like File Explorer and the Start menu load correctly in safe mode again.

Additionally, apps such as Sticky Notes and Dxdiag won’t crash anymore for users with Hebrew or Arabic display languages, thanks to a fix in msftedit.dll.

Known Issues to Watch Out For

Despite the improvements, some issues remain. If you’re on a Copilot+ PC and switch to the Canary Channel, you might lose Windows Hello PIN and biometrics temporarily. The error code 0xd0000225 appears, but you can fix it by resetting your PIN.

Other quirks include:

Taskbar not showing acrylic material after upgrade
High-sampling audio devices (192Hz+) failing to produce sound
Pen input may become unresponsive on some devices
Task Manager search and filtering options not working

Microsoft is actively investigating and working on fixes for these issues. Insider feedback is crucial for smoothing out these rough edges.

What Insiders Should Keep in Mind

The Canary Channel is the bleeding edge of Windows development. Builds here showcase the latest platform changes but may never reach public release. Features can change, disappear, or evolve based on feedback.

“Features may change over time, be removed, or replaced and never get released beyond Windows Insiders.”

Also, switching out of the Canary Channel requires a clean Windows 11 install. Expect a watermark on the desktop indicating the pre-release status.

For a full rundown of builds across Insider channels, check out Microsoft’s Flight Hub.

Final Thoughts

Windows 11 Build 27863 offers a sneak peek at future cryptographic standards and fixes critical bugs. However, it’s still a work in progress with some rough spots. If you’re comfortable with early-stage software, dive in and share your feedback. Otherwise, waiting for Dev or Beta Channel releases might be safer.

Stay tuned for more updates as Microsoft continues refining Windows 11’s next-gen features.

Supports new post-quantum signature algorithm ML-DSA in cryptography APIs for enhanced security.

Fixes Windows Sandbox launch errors and core Windows surfaces failing in safe mode.

Addresses crashes in apps like Sticky Notes for Hebrew and Arabic users.

Known issues include taskbar transparency glitches and audio problems on high-sampling devices.

Switching channels requires a clean Windows 11 install; localization updates are ongoing.

From the Windows Blog