Intel Corporation

Jonathan Mark Lutz

Vedvyas Shanbhogue

Jason W Brandt

Ittai Anati

Hisham Shafi

Michael Neve De Mevergnies

Enrico David Carrieri

Reouven Elbaz

Aditya Katragada

Neel Piyush Shah

Bhavana Prabhakar

A processor that was manufactured by a manufacturer comprises privileged debug operational circuitry, a debug restriction fuse, a credential store, a credential of the manufacturer in the credential store, and debug control circuitry. The debug restriction fuse is a one-time programmable fuse. The debug control circuitry is to automatically restrict access to the privileged debug operational circuitry, based on the debug restriction fuse. The processor may also include public debug operational circuitry, a prevent-unauthorized-debug (PUD) fuse, and an undo-PUD fuse. When the PUD fuse is set and the undo-PUD fuse is clear, the debug control circuitry may respond to an attempt by a debugger to use the public debug operational circuitry by determining whether the debugger is authorized, disallowing access if the debugger is not authorized, and allowing access if the debugger is authorized. Other embodiments are described and claimed.

Technology for controlling access to processor debug features

A processor or system includes a processor core to execute a set of instructions to determine that a memory encryption mode is enabled. The memory encryption mode is to cause data stored to memory to be encrypted and data retrieved from the memory to be decrypted. The processor core is further to determine that a debug mode has been enabled and, responsive to a determination that the debug mode has been enabled, generate a second encryption key different than a first encryption key employed before reboot of a computing system. The processor core is further to transmit the second encryption key to a cryptographic engine for use in encryption and decryption of the data according to the memory encryption mode.

Preventing unauthorized access to encrypted memory

Growing community of inventors

Cornelius, OR, United States of America

Jonathan Mark Lutz