Research On Improving PUF Reliability Based On FPGA

With the rapid development of information technology,the hardware security and credibility,which acts as an important part in information security,have followed more and more attention.Traditional methods based on cryptography are mostly implemented through DES,RSA,AES and etc algorithm encryptions which have high security themselves,but it cost a lot to be deciphered,if the attacker gets the key storage via physical attacking,the whole security mechanism will fail.Contrary to the traditional cryptography methods,PUFs extract signatures from complex inherent properties of physical materials rather than store them in non-volatile memory.Consequently,the keys generated by PUF offer the advantages of low cost,volatile,unpredictable and simple in structure,it is thus an excellent solution for security related applications,such as chip encryption,key storage,authentication,FPGA intellectual property(IP)protection and ID generation.PUF provides a new and feasible method for the physical security of the chip,it exploits the inevitable process deviation of the chip in the manufacturing process to output security keys.However,due to the threaten of voltage,temperature and device aging,Physical Unclonable Functions(PUF)suffer from the unreliability issue,this is because PUF output is subject to a constant change.To improve the PUF reliability,a stability test scheme for PUF mapping unit is proposed,which uses ring oscillators as surrounding logic circuits with multiple complexity and multiple frequencies to interfere with the designed PUF prototype circuit,by identifying and discarding the unsuitable slices(which PUF mapping into cells are highly unstable),then the PUF reliability is effectively improved.Experimental results show that surrounding logic circuits with multiple complexity and multiple frequencies can identify different unreliable units,and the number of unreliable units is directly proportional to the complexity of surrounding logic.Moreover,compared with newly published PUF literatures,the PUF circuit possesses nicer statistical characteristic of randomness,low resource consumption,high uniqueness of 49.78% and high stability of 98.00%,its temperature vary from 0? to 120? and voltage vary from 0.85 V to 1.2V,respectively,which makes it better to be applied to the security field.