Secure Element Access Control Using Reboot Flag Authorization

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Solution Overview

Problem

Existing electronic devices face security vulnerabilities where malicious operating systems can bypass authorization states in secure elements, leading to unauthorized access and data extraction during reboot cycles.

Innovation Solution

An integrated circuit with a detector and control circuit is introduced to monitor reboot states and regulate access to secure functions by setting a reboot flag, ensuring authorization is re-established after each reboot, thereby preventing unauthorized access.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If authorization state is persistently stored in secure element at each reboot cycle, then secure applications can maintain trust with secure element, but malicious OS can bypass security and gain unauthorized access to secure functions

Engineering Contradiction:

Improveauthorization state persistenceVSAvoidunauthorized access by malicious OS

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary actions by detecting the reboot state before processing access requests to secure functions. A reboot flag is set when a reboot is detected, and this flag is checked beforehand to determine whether to restrict or allow access, preventing malicious operations before they can execute

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A reboot flag is introduced as an intermediary mechanism between the reboot detection and access control. This flag acts as a mediator that translates the reboot state into access restrictions, adding a security layer that prevents direct bypass of authorization checks by malicious OS

Inventive Principle:

Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If authorization state is cleared after reset operation, then security is enhanced by preventing malicious access, but legitimate applications must re-authorize after each reboot causing operational delays

Engineering Contradiction:

Improvemalicious access preventionVSAvoidre-authorization time for legitimate apps

Core Design Contradiction:

Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The access control system dynamically adjusts its behavior based on the reboot flag state. During reboot (when flag is set), access is restricted to prevent malicious operations. After reboot completes (when flag is cleared), normal authorization proceeds. This dynamic adaptation allows the system to be restrictive when needed and permissive when safe

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS12481763B2System and method for regulating access to secure functions

Publication Date: 2025.11.25 NXP BV

AI summary

A secure element may be coupled to a host and detects a reboot state of the host based on a state of a reset alert signal received from the host. The secure element further generates a reboot flag indicative of a reset operation of the host. Further, the secure element receives an access request from the host to access a plurality of secure functions of the secure element. Based on the access request, the secure element may determine an authorization state between the host and the secure element. The secure element regulates access of the host to the plurality of secure functions based on a status of the reboot flag and the authorization state.