Research And Implementation Of Efficient Key Generator Based On DRAM PUF

As society advances into the era of Io T(Internet of Things),massive amounts of confidential data are stored in various Io T embedded devices,and the investigation of security mechanisms for critical information in embedded devices has become a hot research topic in the field of information security.PUF(Physical Unclonable Functions),as a new hardware information security mechanism,could effectively resist similar malicious attacks on critical data in NVM(Non-Volatile Memory)by extracting random process differences in the manufacturing process of the chip.Among the several types of PUFs,DRAM PUF extracted from the embedded device’s own DRAM(Dynamic Random Access Memory)provide a greater range of application possibilities owing to their cheap cost and ease of implementation.However,since the DRAM PUF response is sensitive to external factors such as temperature and aging effect,it is not suitable for use as a key in information security mechanisms such as encryption and decryption.The fuzzy extraction algorithm was utilized to implement an efficient key generator based on DRAM PUF which is capable of eliminating error messages caused by environmental noise and aging effect,and consistently generating 128-bit keys.Furthermore,by using DRAM cell row as the minimum read unit of PUF response,an efficient method to extract uniformly distributed DRAM PUF sequences was proposed,which takes only 45 s to extract DRAM PUF sequences with 50% decay rate at 25℃,solving the problem that due to the low charge flip rate,it takes longer time(more than 360s)to extract uniformly distributed DRAM PUF sequences based on the charge decay principle and improves the efficiency of DRAM PUF key generation.The DRAM PUF sequences extracted by the method in this paper own high reliability,uniqueness and randomness at the same time.The efficient key generator based on DRAM PUF is implemented on the Raspberry Pi B+embedded platform,and the experimental results demonstrate that the DRAM PUF raw sequence extracted in row owns a reliability of approximately 95.2% and uniqueness of 49.7%,and passes the NIST randomness test.Secondly,the simulation of equipment aging experiments for more than 10 years shows that the reliability of the original DRAM PUF sequence remains around 93%.In addition,over 30,000 keys were extracted from three Raspberry Pi B+ devices at various ambient temperatures,where the number of incorrect keys is 0 and the reliability is greater than 99%.The uniqueness of keys generated from different Raspberry Pi B+ devices is around 47%,and the information entropy values of keys are all 1.0.Last but not least,an image tamper-proof platform based on DRAM PUF keys is proposed as a practical application scenario for DRAM PUF keys.In summary,the efficient key generator based on DRAM PUF presented in this paper is capable of efficiently generating reliable security keys for embedded devices with strong security characteristics and has practical engineering application value.