Design And Implementation Of DRAM PUF

With the wide application of embedded system, people becoming more and more concerned about their security. In embedded system, secret key is usually stored in Non-volatile memory. In the case of an attacker can capture devices, the key storage system become very fragile and vulnerable to invasive attack and semi-invasive attack, even causing the entire system failure of embedded system by confidential data leakage. At the same time, entity in embedded system is generally exists such problems as poor computing capacity and limited resources, it is difficult to use traditional key protection mechanism to solve the key leakage problem.To solve key leakage problem in embedded system when they encounter invasive attacks and semi-invasive attack, propose a way to generate and save the key based on Physically Unclonable Functions. DRAM is widely exists in the embedded system, use DRAM PUF to produce and save the key doesn't increase additional hardware circuit and the software processing overhead is small, so it can be applied in the embedded systems whose resource is compact.This paper first introduces the advantages of PUF as key generation circuit, test and verify the feasibility of DRAM as Physically Unclonable Functions. Then in view of the weakness of PUF output with noise and non-uniform distribution, fuzzy extraction technology was studied and designed and use key enrollment process and key reconstruction process to complete post processing of the DRAM PUF output according to fuzzy extraction technology. Key enrollment process and key reconstruction process use BCH error-correcting code to complete input noise error correction and use universal hash function to extract uniform-distributed key.To verify DRAM PUF key generation system, this paper build a prototype system based on Xilinx VC709 development board and VC6.0 platform. Completing the basic function of the input and output of DRAM PUF based on Xilinx VC709 development board, and finish software programming of key enrollment process and key reconstruction process based on VC6.0 platform. Verification results show that the DRAM PUF can successfully completed the key generation.