Compensation Circuit Topology for Constant Current Against SPA Attacks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems on chip are vulnerable to simple power analysis (SPA) attacks due to variations in power consumption, which can be used to deduce operational activities. Current compensation circuits are not responsive enough to high-frequency operations, leading to delays and power consumption issues that can reveal operational signatures.
Innovation Solution
An electronic device with a compensation circuit that includes a current source and a compensation stage with resistors and transistors, configured to generate an auxiliary current and an intermediate current. This circuit consumes additional current to maintain a constant total current drawn from the power supply, effectively smoothing the current and concealing the electronic module's current consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If a multi-stage compensation circuit with multiple amplifiers is used to smooth current consumption, then the current smoothing performance is improved, but the device complexity increases and additional delays are generated that reduce responsiveness to high-frequency operations
Solution Approach 1:
The patent extracts the essential compensation function from a complex multi-stage circuit with multiple amplifiers and implements it using a single amplifier in a simplified configuration. The compensation circuit receives the auxiliary current from the voltage regulator and generates a compensating current using only one amplifier, removing unnecessary stages while preserving the current smoothing function.
Solution Approach 2:
Instead of using multiple amplifiers in series to achieve current smoothing, the patent inverts the approach by using a single amplifier with a reconfigured circuit topology. The amplifier controls a switching element that directly modulates the compensating current, achieving the same smoothing effect with reduced complexity and improved responsiveness.
2Stability of the object's composition
If a multi-stage compensation circuit is used to smooth current consumption, then the current smoothing performance is improved, but the power consumption increases
Solution Approach 1:
The patent removes unnecessary amplifier stages from the compensation circuit, keeping only the essential single amplifier needed for current smoothing. This extraction of redundant components directly reduces the power consumption while maintaining the current smoothing function.
Solution Approach 2:
The patent applies partial action by using only the minimum necessary amplification stage (one amplifier instead of multiple) to achieve the required current smoothing effect. This avoids the excessive power consumption that would result from using more amplifiers than necessary.
3Stability of the object's composition
If a multi-stage compensation circuit is used to smooth current consumption, then the current smoothing performance is improved, but the response time increases causing peaks in current delivered that can be exploited in SPA attacks
Solution Approach 1:
The patent extracts and removes the delay-causing multi-stage amplifier configuration, replacing it with a single-stage compensation circuit. This eliminates the propagation delays inherent in multiple amplifier stages, enabling the circuit to respond quickly to high-frequency current variations without generating exploitable peaks.
Solution Approach 2:
The patent implements a direct feedback path in the single amplifier configuration that allows the compensation circuit to rush through the current regulation process without the delays of intermediate stages. The single amplifier directly modulates the compensating current in response to variations in the auxiliary current, achieving fast response suitable for high-frequency operations.
Data Source
AI summary
An electronic device includes a power supply terminal, a voltage regulator connected to the power supply terminal, an electronic module connected to the voltage regulator, and a compensation circuit configured to receive an auxiliary current generated by the voltage regulator and being equal to a first fraction of the electronic module current. The compensation circuit includes a current source configured to supply a source current to a cold point, and a compensation stage connected to the power supply terminal and being traversed by an intermediate current equal to a difference between the source current and the auxiliary current and by a complementary current equal to the intermediate current multiplied by an inverse multiplication factor of the first fraction.