Complementary Security Trace Circuit for Low-Power Active Shielding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated circuit security traces are vulnerable to unauthorized access and data corruption due to unintended capacitive coupling, which causes signal distortion and potential data errors.
Innovation Solution
A complementary-output driver circuit is implemented using a pair of conductive security traces with a clock generator providing complementary voltage levels, switches for isolation and voltage boosting, and comparators for logical signal combination, which cancels induced voltages and reduces power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a top-level conducting trace layer is added to provide electromagnetic shielding and security, then security against unauthorized access is improved, but power consumption increases due to active driving requirements
Solution Approach 1:
The patent combines two security traces into a single differential pair that shares a common driver circuit. The complementary traces are driven together by one driver instead of requiring separate active drivers, reducing power consumption while maintaining security functionality through differential signaling that provides electromagnetic shielding and unauthorized access detection.
Solution Approach 2:
The patent changes the driving mode from single-ended active driving to differential driving with complementary voltage levels. By using complementary traces with opposite voltage swings and connecting them through a transmission gate, the system achieves security functions with reduced power consumption while maintaining signal integrity through differential signaling principles.
2Reliability
If complementary voltage levels are applied to security traces, then electromagnetic shielding effectiveness is improved, but unintended capacitive coupling causes signal distortion
Solution Approach 1:
The patent introduces a transmission gate as an intermediary element between the complementary traces. This transmission gate acts as a controlled connector that equalizes voltages between the two traces during specific phases, mediating the capacitive coupling effects and preventing signal distortion while allowing the complementary traces to maintain their electromagnetic shielding function.
Solution Approach 2:
The patent employs comparators that monitor the voltage levels on the complementary traces and provide feedback control. The comparators detect voltage differences and control the transmission gate to equalize potentials, creating a feedback mechanism that compensates for capacitive coupling effects and maintains signal integrity while preserving electromagnetic shielding effectiveness.
3Reliability
If voltage changes are applied to security traces for active monitoring, then detection of unauthorized access is improved, but power consumption increases
Solution Approach 1:
The patent merges the monitoring function into the differential pair structure, where unauthorized access detection is achieved through the voltage comparison mechanism inherent in the differential signaling. The comparators monitor voltage differences between the complementary traces for security detection purposes without requiring additional active driving power, as the monitoring leverages the existing voltage swings already present in the differential system.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution effectively secures integrated circuits by canceling induced voltages and reducing power requirements, thereby preventing data corruption and enhancing security while conserving energy.
Implementation Method 1
An inherent feature of an active security trace system is that, when the voltage of the security trace layer changes, that change induces a related change in any adjacent conductors through the capacitance between the security trace layer and the adjacent conductors.
Implementation Method 2
The top-level conducting trace layer provides an electromagnetic shield for underlying circuits from interference caused by external electromagnetic signals.
Data Source
AI summary
The present invention provides a method and apparatus for securing an integrated circuit. A pair of conductive security traces are arranged on an integrated circuit. Driver means provide complementary HIGH and LOW voltage levels to a respective first end of each of the conductive security traces. A first switch means temporarily interrupts the driver means and isolates the pair of conductive security traces. A second switch means temporarily connects the first ends of the isolated pair of conductive security traces to each other so that both conductive traces are at the same voltage. The voltage at the first end of one of the security traces at the LOW voltage is then boosted to one-half of the HIGH voltage level (VDD/2) by the HIGH (VDD) voltage level at the first end of the other security trace. First and second comparators are provided, each of which compares voltages on their respective first ends of the pair of conductive security traces with voltages on a respective second end of the pair of conductive security traces. Means are provided for logically combining the output signals of the first and second comparators.