Design Of DPA Countermeasures For Lightweight Block Cipher Of IoT Devices

With the development of technology,the number of Io T(Internet of Things)devices have skyrocketed.This has greatly facilitated people's lives,but it has also brought new security issues.Cryptographic algorithms are the cornerstone of Io T devices.In order to reduce the resource consumption of cryptographic algorithms on Io T devices,new lightweight block ciphers are constantly being proposed in recent years.Lightweight block ciphers consume less resources than traditional block ciphers,but also face the threat of Differential Power Analysis(DPA).The traditional countermeasures against DPA pay more attention to the improvement of safety and the reduction of frequency loss,which require a large area overhead and are no longer suitable for the protection of Io T devices.Therefore,some DPA countermeasure with low areaoverhead are needed.In this thesis,three low area-overhead countermeasures are designed to resist DPA,implemented and tested respectively.The first countermeasure is Random Register Group.This countermeasure randomly divides the data into two groups according to the register enable signal,and writes the data into the register twice.On the basis of this countermeasure,this thesis discusses the effect of effective register enable signal bits on the Random Register Group,and then combines the random precharge countermeasure to further improve safety.The second countermeasure is Circular-Shift,which can write data into registers after being shifted as a whole.The third countermeasure is Fixed Permutation-Table,which can reorganize the original data based on basic unit of bit and write data into registers.The latter two methods increase the difficulty of the attack by breaking the matching relationship between the intermediate value and energy consumption.At the same time,they do not require a true random number generator,so they have lower implementation difficulty than the first method.Although the third method and the second method are also based on bitpermutation,the third method is aimed at the weaknesses of the second method(attacks with known protection method)are optimized and therefore have higher security.The power analysis attack platform is built based on the SAKURA-G board designed for research on hardware security,lightweight block cipher SKINNY,SIMON and traditional block cipher AES(Advanced Encryption Standard)are selected as test algorithms,and the Hamming distance model is selected to verify the security of the proposed countermeasures.The experimental results show that for SKINNY and SIMON algorithm,the three countermeasures,for SKINNY and SIMON algorithms,can resist at least 100 thousand energy trace differential power analysis with 0.6%?29.7% of area-overhead and losing 40.7%?48.5% of throughput.Combining theoretical analysis and test results,the Fixed Permutation-Table countermeasure has the best effect among the three methods.Compared with the Circular-Shift countermeasure,this method greatly improve the safety of cryptographic device with a low additional area.Meanwhile,it has higher security and lower additional area than Random Register Group.This method for AES algorithm compared with traditional methods,can resist at least 1 million energy traces DPA with 4.7% of area-overhead and losing 10.8% of throughput.Experimental results show that Fixed Permutation-Table countermeasure can significantly improve the ability of cryptographic devices to resist DPA with low area overhead and throughput loss.