Image Sensor Security Circuit DPA Attack Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image sensors are vulnerable to differential power analysis (DPA) attacks, which can compromise the security of private keys used in image processing systems, particularly in autonomous driving applications where accurate lane detection and vehicle control are critical.
Innovation Solution
The proposed solution involves an image sensor with a security circuit that includes a crypto module and a DPA countermeasure module. The crypto module decrypts cipher text using a private key, while the DPA countermeasure module uses random numbers generated from the cipher text to defend against DPA attacks. Additionally, the image sensor stores an encoded private key in a non-volatile memory (NVM) to prevent key leakage during decryption operations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a private key is stored in non-volatile memory for secure decryption operations, then key security is improved, but the system becomes vulnerable to differential power analysis (DPA) attacks that can extract the private key through power consumption analysis
Solution Approach 1:
The patent applies preliminary action by generating and storing random numbers in advance within the non-volatile memory alongside the private key. These pre-generated random numbers are then used during decryption operations to mask the power consumption patterns, preventing DPA attacks from extracting the private key through power analysis.
Solution Approach 2:
The patent uses random numbers as an intermediary element between the private key and the power consumption signal. These random numbers mask the correlation between the private key operations and power consumption, acting as a mediator that breaks the direct link that DPA attacks exploit to extract cryptographic keys.
2Reliability
If random numbers are generated and used for DPA countermeasures during decryption operations, then protection against DPA attacks is improved, but the device complexity increases due to additional security circuitry
Solution Approach 1:
The patent merges the DPA countermeasure functionality with the existing decryption circuitry by integrating the random number generation and usage into the security circuit that handles key operations. This combination approach provides DPA protection while minimizing additional complexity by reusing existing circuit resources for both decryption and countermeasure functions.
Solution Approach 2:
The security circuit is designed with multi-functionality, serving both the decryption operation and the DPA countermeasure functions. The same circuit infrastructure handles both the private key decryption operations and the random number generation for masking power consumption, making the security circuit universal and reducing overall device complexity.
3Reliability
If the image sensor includes integrated security circuits for DPA protection and key management, then cybersecurity is improved, but the area occupied by the image sensor increases
Solution Approach 1:
The patent applies the nesting principle by placing the security circuits, including random number generators and DPA countermeasure modules, within the existing pixel array or control logic structure of the image sensor. This nested integration allows security functionality to be embedded in the sensor's existing architecture, minimizing additional area occupation while providing comprehensive cybersecurity protection.
Solution Approach 2:
The patent utilizes the vertical dimension by stacking security circuits on top of or alongside the pixel array in a three-dimensional architecture. This dimensional approach allows the image sensor to incorporate DPA protection and key management capabilities without proportionally increasing the planar area, as the security functions are added in the vertical dimension rather than expanding the sensor footprint.
Data Source
AI summary
An image sensor includes a non-volatile memory (NVM) storing a encoded private key and partial information of a private key, using first random numbers generated by repeating a first random number generation operation using the partial information of the private key, and a security circuit that performs a decryption operation on a cipher text received from a controller. The security circuit includes a self-recursive decoder that receives the encoded private key from the NVM during the decryption operation, repeats a second random number generation operation using the partial information of the private key to generate second random numbers, and uses the second random numbers to restore the encoded private key to the private key, and a crypto module that uses the restored private key to decrypt the cipher text.