CSRO-Based Reconfigurable True Random Number Generator Using RRAM

In this paper, we propose a high-speed (kilohertz-megahertz), reconfigurable current starved ring oscillator (CSRO)-based true random number generator (TRNG) design. The proposed TRNG exploits the intradevice stochastic variations in resistive RAM switching parameters and random telegraph noise (RTN). We demonstrate the effect of RTN on the jitter of CSRO oscillations. We also propose a methodology to reconfigure the TRNG to generate new random numbers. The proposed 10-bit TRNG is validated by NIST test suite for randomness in the data stream. Energy/bit is 22.8 fJ for generation, and the speed of random data generation is 6 MHz. Security vulnerabilities and countermeasures of the proposed TRNG are also investigated.