On the Entropy of Oscillator-Based True Random Number Generators under Ionizing Radiation.

Area of Science:

• Electronics
• Radiation Effects
• Computer Engineering

Background:

• Field-programmable gate arrays (FPGAs) are susceptible to ionizing radiation.
• Previous studies focused on deterministic FPGA behaviors under radiation.
• True Random Number Generators (TRNGs) are critical for secure applications.

Purpose of the Study:

• To investigate the impact of ionizing radiation on FPGA-based TRNGs.
• To quantify the degradation of TRNG randomness quality with accumulated radiation dose.
• To compare the radiation sensitivity of TRNGs versus deterministic FPGA elements.

Main Methods:

• Two FPGA-based TRNGs sampling jittery signals were exposed to a Co-60 radiation source.
• Accumulated radiation dose was systematically increased.
• National Institute of Standards and Technology (NIST) statistical test suites evaluated TRNG randomness (entropy, linear complexity).

Main Results:

• TRNG randomness quality significantly degraded with increasing accumulated radiation dose.
• Statistical properties of the TRNGs showed a clear dose-dependent deterioration.
• Degradation of the non-deterministic TRNG component occurred before deterministic FPGA elements.

Conclusions:

• Ionizing radiation negatively impacts the performance of FPGA-based TRNGs.
• The radiation-induced degradation of TRNGs is a critical factor for system reliability.
• TRNGs are more sensitive to radiation than deterministic FPGA logic, posing an early failure risk.