Digital Anti-Tampering Detector for Chip Physical Attack Detection
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Solution Overview
Problem
Existing anti-tampering detection circuits in chips are prone to errors due to the need for expensive calibration and are affected by operating temperature and voltage, making it difficult to correctly detect various types of physical attacks.
Innovation Solution
An anti-tampering detector comprising a temperature sensor, a voltage detector, a frequency detector, and a controller, which generates detection results based on temperature, voltage, and frequency codes, allowing the chip to activate protection mechanisms against physical attacks without introducing side effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If analog circuits or mix-signal circuits are used for detection, then detection capability is achieved, but calibration cost increases and detection accuracy deteriorates due to temperature and voltage effects
Solution Approach 1:
The patent replaces analog detection circuits with a digital detection system that uses digital counters and logic circuits to measure frequency. This substitution eliminates the need for expensive analog calibration while maintaining detection accuracy, as digital circuits are inherently more stable against temperature and voltage variations.
Solution Approach 2:
The patent changes the detection approach from measuring analog voltage levels directly to measuring frequency parameters through counter circuits. By counting clock cycles over a specific period, the system converts physical quantity measurement into a digital time-based measurement, which is less susceptible to environmental variations.
2Adaptability or versatility
If multiple types of physical attacks are detected, then comprehensive protection is achieved, but detection complexity increases
Solution Approach 1:
The patent implements a universal detection mechanism that can identify multiple types of physical attacks (voltage attacks, frequency attacks, clock glitch attacks, temperature attacks) using a single integrated digital detection system. The controller coordinates multiple detectors to provide comprehensive protection without requiring separate complex circuits for each attack type.
Solution Approach 2:
The patent divides the detection system into separate functional modules: voltage detector, frequency detector, and temperature sensor, each handling specific attack types. This segmentation allows independent optimization of each detector while maintaining overall system simplicity through modular architecture.
3Loss of information
If analog signals are used for representing operation conditions, then information representation is achieved, but susceptibility to noise and interference increases
Solution Approach 1:
The patent replaces analog signal representation with digital signal representation throughout the detection system. Operation conditions are represented as digital values from counters and sensors, which are inherently immune to noise and interference, eliminating the need for complex analog signal conditioning and filtering.
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
The solution effectively monitors operation conditions and detects physical attacks, ensuring accurate detection of tampering attempts without the need for expensive calibration and minimizing the impact of temperature and voltage variations.
Implementation Method 1
generating a temperature code according to a first clock output from a proportional to absolute temperature (PTAT) oscillator
Implementation Method 2
generating a voltage code according to a second clock output from a voltage controlled oscillator (VCO)
Data Source
AI summary
An anti-tampering detector and a method for detecting a physical attack are provided, wherein the anti-tampering detector includes a temperature sensor, a voltage detector, a frequency detector and a controller. The temperature sensor is configured to generate a temperature code according to an operation temperature. The voltage detector is configured to generate a voltage code according to a supply voltage and the temperature code. The frequency detector is configured to generate a frequency code according to a system clock, the temperature code and the voltage code. The controller is configured to generate an anti-tampering detection result according to the temperature code, the voltage code and the frequency code. The anti-tampering detection result indicates whether any of the operation temperature, the supply voltage and the system clock is tampered with due to the physical attack.