Aiming at low power consumption demand of cipher security application process in wireless sensor networks（WSNs） and the tendency of integration and micromation of WSNs

a novel design method of true random number generator（RNG） is proposed to generate high quality keys which guarantee the security of cryptographic algorithms.This method constructs Fibonacci oscillating RNG based on probability calculating cells.Because working state of probability calculating cells are in sub-threshold current range of MOSFET

small working current makes power consumption minimized.Meanwhile

to prevent circuit to stop oscillating

so-called probability signal amplification cell is designed to guarantee correction of random oscillation.Simulation test is performed in SMIC 0.13 μm process.Randomness of the output random sequence is pretty well.Compare to the Fibonacci oscillating RNG based on digital logic gates

power consumption of this design is reduced 1 000 times and the area is significantly reduced too

therefore it is suitable for WSNs applications.