Authentication Module for Secure Debug Port Access Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing electronic devices lack effective authentication mechanisms to control access to internal resources, particularly for debug ports, which can lead to unauthorized access and potential security breaches.

Innovation Solution

The implementation of an authentication module that maps authorization requests from test devices to specific resources, using a decode/translate module and verification module to authenticate access, and a secure fuse processor to manage access levels, ensuring only authorized devices can access system resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If debug ports are made accessible for testing and debugging purposes, then device functionality and testability are improved, but security risks and unauthorized access potential increase

Engineering Contradiction:

ImprovetestabilityVSAvoidunauthorized access

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

An authentication module is introduced as an intermediary component between the debug port and the electronic device's internal resources. This module receives authentication requests from external devices, verifies credentials, and controls access to debug resources. The intermediary layer maintains testability by allowing legitimate access while preventing unauthorized access through cryptographic verification of authentication credentials.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If authentication mechanisms are added to debug ports, then security is improved, but device complexity increases

Engineering Contradiction:

ImprovesecurityVSAvoidauthentication module

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The authentication functionality is segmented into a separate, dedicated authentication module that operates independently from the main device logic. This module contains specialized authentication state machines and cryptographic verification logic, isolating complexity to a specific component. The segmentation allows the rest of the device to remain simple while security-critical functions are handled by the specialized authentication module.

Inventive Principle:

Principle #1Segmentation

3Measurement precision

If multiple debug ports are authenticated independently, then access control precision is improved, but authentication overhead and time increase

Engineering Contradiction:

Improveaccess controlVSAvoidauthentication time

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

Authentication credentials are pre-configured and stored in secure non-volatile memory within the authentication module before device operation. The authentication state machines are pre-programmed with verification logic for multiple debug ports. When a debug port connects, the pre-configured credentials and verification logic enable rapid authentication without requiring real-time credential distribution or complex verification algorithms, reducing authentication time while maintaining precise access control.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS8276199B2Method and device for secure test port authentication

Publication Date: 2012.09.25 NXP USA INC

AI summary

A device includes a first test port coupled to a first test device, a second test port coupled to a second test device, a resource, and a security controller coupled to the first and second test ports. The security controller is operable to authenticate the first test device prior to authenticating the second test device, and, in response to authenticating the first test device, permit the first and second test devices to access the first resource.