Security Shield Wiring Structure for Reverse Engineering Resistance

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional FPGAs and ROMs face security issues with unauthorized access to circuit wiring and operating signal information through operational analysis, requiring costly and inflexible encryption technologies that lack versatility.

Innovation Solution

A security wiring structure with unique characteristics is provided on the device, covered by a synthetic resin, making it non-removable and resistant to external analysis, with a configuration that prevents operation if damaged or removed, and uses a unique operating key based on signal combinations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional ROM is used to store circuit wiring information, then the device can operate with programmed logic, but the ROM contents can be easily read by third parties using ROM writers

Engineering Contradiction:
Improveprogrammability of logic circuitsVSAvoidsecurity against unauthorized reading
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

A security wiring structure acts as an intermediary between the ROM and the FPGA, preventing direct access to ROM contents while allowing authorized operation. The structure includes security wiring that must be intact for the device to function, and opaque resin that prevents visual inspection of wiring positions, thereby mediating between operational needs and security requirements

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The security system segments the protection mechanism into multiple components: opaque resin covering the wiring positions, security wiring with unique patterns, and detection circuitry. This segmentation allows each component to perform its specific function while collectively providing robust security against unauthorized reading

Inventive Principle:
Principle #1Segmentation

2Reliability

If encryption technologies are incorporated into FPGAs and ROMs, then reverse engineering resistance is enhanced, but the cost increases and existing devices cannot be retrofitted

Engineering Contradiction:
Improvereverse engineering resistanceVSAvoidcost and versatility
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of requiring expensive front-end encryption processes during manufacturing, the invention uses opaque resin to create a visual barrier that copies the effect of security without the complex encryption hardware. This allows existing devices to be retrofitted with security by simply adding the opaque resin and security wiring structure

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The invention changes the parameter of security from electronic encryption to physical-visual obstruction combined with wiring integrity verification. By changing how security is implemented (from digital encryption to physical barrier plus integrity check), the system becomes cheaper and compatible with existing devices while maintaining reverse engineering resistance

Inventive Principle:
Principle #35Parameter changes

3Difficulty of detecting and measuring

If the wiring structure is made visible from outside, then operational analysis can be performed, but security against unauthorized access is compromised

Engineering Contradiction:
Improvevisibility of wiring positionsVSAvoidsecurity against operational analysis
Core Design Contradiction:
Difficulty of detecting and measuringVSReliability

Solution Approach 1:

The invention uses opaque resin with specific optical properties that block light transmission, preventing visual detection of wiring positions underneath. This color/optical property change ensures that even if the wiring is physically present, its position cannot be detected through visual inspection or optical methods

Inventive Principle:
Principle #32Color changes

Data Source

PatentEP4660861A1Device security shield structure
Publication Date: 2025.12.10 CONNECTEC JAPAN CORP
  • EP4660861A1 patent drawingFigure 1~2
  • EP4660861A1 patent drawingFigure 3~4
  • EP4660861A1 patent drawing

AI summary

[PROBLEM] To provide a groundbreaking device security shield structure that can achieve high reverse engineering resistance with an inexpensive implementation technology and is also highly versatile through post-processing on existing devices. [SOLUTION] A device security shield structure wherein a security wiring structure 4, comprising wiring 3 or the like and having a unique characteristic, is provided on an upper portion of a device 2 on a substrate 1, and this wiring structure 4 is covered with a synthetic resin 5, creating a configuration where it cannot be removed or be subject to external operational analysis measurement unless the wiring structure 4 is damaged. The acquisition of said unique characteristic is made an operating condition of the device 2, whereby if the wiring structure 4 is damaged or removed, the device 2 does not operate and operational analysis becomes impossible.