Integrated Photocurrent Sensing for Laser Attack Detection in Secure ICs
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Solution Overview
Problem
Existing countermeasures against laser-based attacks on integrated circuits, such as physical barriers and redundancy, face limitations in compatibility, performance impact, and cost, while being vulnerable to increased light intensity and complex attacks.
Innovation Solution
Implementation of photocurrent detection circuits within integrated circuits, comprising asymmetrically sized N-type and P-type MOS devices, forming logic circuits that detect changes in logic states induced by radiation, allowing for early detection and countermeasures like disabling buffers and resetting the circuit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If physical barriers (metal shields) are used to block laser attacks, then protection against laser-based attacks is improved, but compatibility with IC fabrication limits and circuit performance is degraded
Solution Approach 1:
The patent replaces physical mechanical barriers (metal shields) with an electronic detection system using photocurrent detection circuits. The detection circuit monitors for laser-induced photocurrents and triggers countermeasures, substituting the need for physical shielding while maintaining protection effectiveness.
2Reliability
If redundancy is used to detect corrupted circuit operation, then detection capability is improved, but silicon area cost and circuit complexity increase
Solution Approach 1:
The patent introduces an intermediary detection circuit that monitors for laser attacks independently of the main logic circuits. This photocurrent detection circuit acts as a mediator that detects attacks before they corrupt logic operations, avoiding the need for complex redundant logic paths while maintaining detection capability.
3Productivity
If devices with inherent low photonic sensitivity are used, then normal circuit operation is improved, but vulnerability to laser attacks increases
Solution Approach 1:
The patent segments the circuit into two functional parts: normal logic circuits with standard photonic sensitivity for optimal performance, and dedicated photocurrent detection circuits with high sensitivity for attack detection. This segmentation allows each part to be optimized for its specific function without compromise.
4Reliability
If shielding approaches are used to block laser light, then protection against attacks is improved, but circuit performance limitations and fabrication compatibility worsen
Solution Approach 1:
The patent replaces mechanical shielding approaches with an electronic detection and response system. The photocurrent detection circuit electronically identifies laser attacks and triggers software or hardware countermeasures, eliminating the performance penalties associated with physical shielding while maintaining protection effectiveness.
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
Enhances the ability to detect and respond to laser-based attacks effectively, reducing the risk of data corruption and system vulnerability by leveraging the same physical mechanism used in attacks for protection, with improved sensitivity and response times.
Implementation Method 1
Pulsed lasers provide a convenient and easily controlled method for introducing such faults by creating transient currents in PN junctions or device channels through the photo-electric effect
Data Source
AI summary
Various embodiments include integrated approaches to detecting attempts to breach system-level or chip-level security using photo-generated currents induced by lasers or other radiation sources. Various embodiments integrate photo-detection circuits with a secure processor or other circuit in such a manner that the response to a security attack is fast enough to prevent loss of secure or private information are described. Various embodiments include circuits capable of providing a permanent record of photocurrent detection.