Secure World Data Input Method with Segmented Display Area

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Solution Overview

Problem

In the TrustZone technology, the security of events generated when a user operates a program in the Normal World of user equipment cannot be completely ensured, and events in the Normal World cannot be directly operated.

Innovation Solution

A data input method that uses a display unit to present an input area to the user, with a non-secure core receiving events from a touch panel and determining if they are secure input events. If secure, the method triggers a TZ driver to switch to a secure core environment, where a preset display area is started for secure input operations, and events are delivered to the first operating environment for processing when the user operates outside this area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the displayed content covers the entire display area in the Secure World, then the security of data input is improved, but the user cannot view other events (e.g., short message service messages) without quitting the data input environment

Engineering Contradiction:
Improvesecurity of data inputVSAvoiduser operation flexibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The display area is segmented into a first display area (for Secure World content) and a second display area (for Normal World content). This allows both secure data input and other user operations to coexist simultaneously on the same display without requiring the user to quit the secure environment, thus resolving the contradiction between security and operational flexibility.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the system quits the data input environment to view other events, then the user can access other applications, but the previously operated event is lost

Engineering Contradiction:
Improveaccess to other applicationsVSAvoidloss of previously operated event
Core Design Contradiction:
Adaptability or versatilityVSLoss of information

Solution Approach 1:

The system performs preliminary action by saving the current input content and operation state before the user switches to view other events in the second display area. This ensures that when the user returns to the first display area, the previously operated event is restored, preventing information loss while allowing access to other applications.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If hardware composition is divided into Secure World and Normal World with complete isolation, then security level is improved, but events in Normal World cannot be directly operated

Engineering Contradiction:
Improvesecurity levelVSAvoiddirect operation of Normal World events
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

A message processing mechanism acts as an intermediary between the Secure World and Normal World. The second display area displays events from the Normal World, and when the user operates these events, the system processes them through the secure interface. This allows direct operation of Normal World events while maintaining security through the mediating message processing system.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3418934B1Data input method, device and user equipment
Publication Date: 2025.02.19 HUAWEI TECH CO LTD
  • EP3418934B1 patent drawingFigure 1A
  • EP3418934B1 patent drawingFigure 1B
  • EP3418934B1 patent drawingFigure 2

AI summary

A data input method and apparatus, and user equipment are provided. The method includes: when it is determined that an operation of a user on the user equipment UE is not performed in a preset display area, deliver an event corresponding to the operation to a first operating environment for processing, where the preset display area runs in a second operating environment of the UE, and the second operating environment has a higher security level than the first operating environment. This can better improve security of an event generated when the user operates a program that runs in a Normal World of the user equipment, and can directly operate an event that runs in the Normal World.