Power Supply Current Masking for Side-Channel Attack Prevention
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Solution Overview
Problem
Existing electronic circuit power supply devices are vulnerable to attacks where attackers measure current variations to deduce confidential information, compromising the security of sensitive data such as passwords and encryption keys.
Innovation Solution
A power supply system that uses a current mirror configuration with transistors and operational amplifiers to regulate the voltage and current, ensuring that the total current consumed remains constant, thereby masking any variations in current consumption and preventing attackers from extracting sensitive information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional power supply device delivers stabilized voltage to the electronic circuit, then the voltage remains constant during current variations, but the current variations reveal confidential information about circuit operation
Solution Approach 1:
The patent introduces an intermediary power supply device between the power source and the electronic circuit. This device acts as a mediator that decouples the relationship between circuit operation and observable current consumption. The intermediary regulates current flow using control signals derived from the stabilized voltage, ensuring that current variations do not directly reflect circuit state while maintaining proper voltage supply.
Solution Approach 2:
The patent implements a feedback mechanism where the power supply device continuously monitors the stabilized voltage output and uses it to generate control signals for current regulation. This feedback loop ensures that the device adjusts its current consumption dynamically to maintain constant total current while preserving voltage stability, thereby preventing information leakage through current measurements.
2Ease of operation
If the power supply device maintains constant voltage for circuit operation, then the circuit functions properly, but current variations occur that can be measured and used for attacks
Solution Approach 1:
The patent converts the harmful effect of current variations into a beneficial feature by designing the power supply device to intentionally consume variable current that compensates for circuit current changes. The device uses the same voltage stabilisation mechanism that causes current variations to instead create masking current variations, transforming a security vulnerability into a security feature where total current remains constant.
Solution Approach 2:
The patent changes the parameter being monitored from circuit current to total current (circuit current plus device current). By controlling the total current to remain constant while allowing internal parameter changes in both the device and circuit, the system maintains circuit functionality while eliminating the security vulnerability associated with measuring circuit current variations.
3Loss of information
If the power supply device compensates for current variations to mask information, then security is improved, but the device complexity increases
Solution Approach 1:
The patent achieves multi-functionality by designing the power supply device to simultaneously perform voltage stabilisation and current masking. The same control mechanism that regulates voltage output also generates the control signals for current compensation. This universal approach allows a single device to provide both power supply and security functions, reducing overall system complexity compared to having separate voltage regulation and current masking devices.
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 protects the electronic circuit against attacks by maintaining a constant current consumption, making it impossible for attackers to deduce confidential data from current variations, thus enhancing the security of sensitive information.
Implementation Method 1
flow a third current through a second conductor connected to the node, a first branch of a current mirror conducting the third current
Implementation Method 2
regulate a potential of the node by acting on a gate potential of a transistor electrically in series with a second branch of the current mirror
Implementation Method 3
an operational amplifier receives a potential difference between the node and the terminal of the second branch of the other current mirror and acts on the gate potential of the transistor
Data Source
AI summary
The present invention concerns an electronic circuit power supply device, configured to: flow, through a first conductor connected to a node, a first current that is an image of a second current consumed by the electronic circuit; flow a third current through a second conductor connected to the node, a first branch of a current mirror conducting the third current; flow a fourth constant current through a third conductor connected to the node; consume a fifth current that is an image of the third current; and regulate a potential of the node by acting on a gate potential of a transistor electrically in series with a second branch of the current mirror.