Windows 11 Encryption Bug Can Cause 'Data Damage' for Latest CPUs

pcmag.com:

Microsoft is warning about a bug in Windows 11 that might lead to “data damage” for PCs running new CPUs that support the latest encryption protocols. 

Redmond has been vague on the details, including the severity, but the issue can affect storage encryption programs such as BitLocker.

According(Opens in a new window) to Microsoft’s report, the bug can be triggered for Windows 11 devices running the latest Vector Advanced Encryption Standards instruction sets. Specifically, AES XEX-based tweaked-codebook mode with ciphertext stealing (AES-XTS) or AES with Galois/Counter Mode (GCM) (AES-GCM).

These instruction sets can be used over newer CPUs to run encryption for BitLocker and drive storage programs from Kingston. Microsoft accidentally created the bug when it “added new code paths” to take advantage of the encryption protocols. 

Microsoft hasn’t said which CPUs are affected. But Intel has been implementing the AES-GCM encryption protocol since 2010, according(Opens in a new window) to a company document. The same bug also affects systems running Windows Server 2022. 

Microsoft rolled out two patches in May and June to address the issue, but those patches led to a “two-times” performance drag for Windows 11 PCs when running encryption-based operations. The performance hit could appear for BitLocker, the Transport Layer Security (TLS), which is used to encrypt data over a web browser, and during disk throughput operations, especially for enterprise customers. 

So if you experienced slow PC speeds earlier this summer, this bug might explain it. The good news is that Microsoft released another two patches to fix the problems with the originals, which it recommends you install immediately.

“If this affects you, we strongly