What encryption method is used on Microsoft Windows computers to protect data at rest, and uses Advanced Encryption Standard (AES)?

The correct answer is BitLocker, which is a full disk encryption feature included in Microsoft Windows operating systems. BitLocker uses the Advanced Encryption Standard (AES) to provide robust protection for data stored on the machine. This encryption ensures that, even if an unauthorized user gains physical access to a computer, they cannot easily access the data without proper authentication.

BitLocker encrypts the entire volume, thereby securing the operating system and all files against tampering and unauthorized access. The additional security comes from the fact that BitLocker can leverage hardware-based security features, such as Trusted Platform Module (TPM), to enhance encryption key management and integrity checks.

In contrast, the other methods mentioned do not primarily focus on protecting data at rest. IPSec is primarily used for securing Internet Protocol communications, TLS provides secure communications over a computer network, and Software Guard Extensions (SGX) are designed to create secure enclaves in memory to protect sensitive data while in use in applications. Therefore, they do not serve the same purpose as BitLocker, which is specifically designed for data encryption on disk drives.