Which of the following technologies encrypts data as it exists in memory to prevent untrusted processes from decoding the information?

The correct choice is Software Guard Extension (SGX) because it is specifically designed to create secure enclaves in memory, allowing sensitive data to be processed in a protected environment. This technology effectively encrypts data while it is being used, ensuring that even if untrusted processes or users attempt to access the memory, they cannot decode the information inside these secure enclaves. This functionality is critical in preventing data breaches and protecting sensitive information from external threats.

In contrast, Secure Authentication refers to methods of verifying the identity of users or devices but does not inherently provide memory encryption. PacketFence is a network access control solution focused on managing devices on a network rather than encrypting data in memory. Poly1305 is a cryptographic message authentication code that ensures data integrity and authenticity but does not address the encryption of data in memory or protect against untrusted processes actively.