Contactless Card Sensor Entropy for Unpredictable Cryptographic Keys
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Solution Overview
Problem
Current contactless cards lack the capability to generate high entropy data and random numbers, which are crucial for secure cryptographic operations.
Innovation Solution
Incorporating sensors such as accelerometers, thermometers, magnetometers, and gyroscopes into contactless cards to capture environmental measurements, which are processed to generate random numbers and cryptographic keys.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If pseudorandom number generators (PRNG) are used to generate random numbers, then the system can produce sequences of numbers, but the numbers are predictable from earlier outputs and not truly random
Solution Approach 1:
The patent replaces the software-based PRNG algorithm with a hardware-based true random number generator that uses physical sensors (accelerometer, thermometer, magnetometer, gyroscope) to capture environmental entropy. This substitution of mechanical/physical measurement systems for computational algorithms eliminates predictability while maintaining randomness generation capability.
2Reliability
If sensors are added to the contactless card to capture environmental measurements, then high entropy data can be generated, but the device complexity increases
Solution Approach 1:
The patent integrates multiple sensor types (accelerometer, thermometer, magnetometer, gyroscope) into a single contactless card device that also performs cryptographic operations. The processing circuitry serves dual purposes: capturing sensor data for entropy generation and executing cryptographic algorithms, thereby reducing overall system complexity despite adding sensor functionality.
Solution Approach 2:
The patent combines the random number generation function with the existing contactless card cryptographic processing unit. The processing circuitry that normally handles cryptographic operations is enhanced to also collect and process sensor data, merging two functions into a single integrated system rather than adding separate hardware components.
3Reliability
If random sampling of sensor data is performed to generate seed values, then true random numbers can be produced, but the processing time and computational overhead increase
Solution Approach 1:
The patent collects and pre-processes sensor data continuously in the background to build up a pool of entropy data before it is needed for random number generation. The processing circuitry accumulates environmental measurements over time, so when random numbers are required, pre-collected high-quality entropy is already available, reducing generation latency.
Solution Approach 2:
The patent performs random sampling of sensor data by selecting only a portion of the collected measurements that meet entropy quality thresholds, rather than processing all sensor data. This partial processing approach generates sufficient random numbers efficiently by focusing computational resources on the most entropy-rich data samples.
Data Source
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AI summary
Embodiments are directed to systems and techniques to generate random numbers via contactless cards.