Extraction of Device Fingerprints Using Built-in Erase-Suspend Operation of Flash Memory Devices

The reliability and efficiency of a physically unclonable function (PUF) considerably depends on that of the random seed number generation process in the target hardware technology. Among the proposed hardware PUF techniques, flash memory-based approaches have several advantages because of the widespread use of flash memories in electronic devices. The operations of the flash memories such as read, program, and erase have been utilized to generate the random number based on their random process variations. In this work, we propose a random number generation method for the flash memory-based hardware PUF applications that utilize the intrinsic erase-suspend operation in modern flash memory devices. Unlike the conventional methods, the proposed method does not require any modification of the device or additional peripheral circuitry to control the operations. We evaluate the proposed method from the perspective of reliability and efficiency. The experimental results show that the proposed method can generate a 16-bit random number in 1 ms approximately while maintaining greater than 95 % reproductivity of the random number.