Challenge-Driven Latch PUF Circuit for Higher Response Entropy
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Solution Overview
Problem
The entropy of generated individual-specific information in latch PUFs remains insufficient, making it difficult to predict changes in response data in response to challenge data.
Innovation Solution
An electronic circuit comprising a first circuit to generate a first output with a first voltage-rise time, a second circuit to vary the output to a second output with a different second voltage-rise time based on challenge data, and a third circuit with an inconstant initial value, where the output value varies with the second voltage-rise time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a latch PUF is used to generate individual-specific information, then the information can be used for authentication, but the entropy of the generated information remains insufficient making it difficult to predict response data changes
Solution Approach 1:
The electronic circuit is divided into three distinct functional circuits: a first circuit for generating a first output signal, a second circuit for varying the output signal based on challenge data, and a third circuit with inconstant initial values that produces final response data. This segmentation allows each circuit to contribute specifically to increasing entropy while maintaining authentication reliability.
Solution Approach 2:
The second circuit dynamically varies the first output signal to a second output signal based on challenge data, and the third circuit's output varies in accordance with the second voltage-rise time. This dynamic behavior ensures high entropy in the response data while maintaining reliability through controlled variability.
2Reliability
If the frequency of clock signal is changed to improve quality of individual-specific information, then some variation is achieved, but the entropy remains insufficient
Solution Approach 1:
Instead of relying solely on clock signal frequency changes, the invention changes multiple parameters including the voltage-rise time of output signals through the second circuit, and utilizes the inconstant initial values of the third circuit. These parameter changes collectively achieve high entropy while maintaining information quality.
3Loss of information
If response data with high entropy is generated to make prediction difficult, then security is improved, but the circuit complexity increases with three separate circuits
Solution Approach 1:
The three circuits are merged into a single integrated electronic circuit that processes challenge data and generates response data in one cohesive system. This merging achieves high entropy for improved security while managing complexity through unified design rather than separate independent systems.
4Loss of information
If the initial value of a circuit is made inconstant to increase entropy, then response data security is improved, but the circuit behavior becomes less predictable
Solution Approach 1:
The third circuit is designed with inconstant initial values as a preliminary condition before operation. This preliminary action of setting unpredictable initial states ensures high entropy in the output while the overall circuit structure maintains stability through defined operational parameters and controlled signal flow.
Data Source
AI summary
An electronic circuit includes the following: a first circuit configured to generate a first output having a first voltage-rise time; a second circuit configured to vary, in accordance with data included in challenge data, the first output to a second output having a second voltage-rise time different from the first voltage-rise time; and a third circuit in which an initial value is inconstant, and in which an output value varies in accordance with the second voltage-rise time.