基于高级加密标准的远场电磁旁路攻击

Far field electromagnetic side channel attack based on advanced encryption standard

电磁旁路攻击是旁路攻击中的一种有效方法,为了克服传统的电磁旁路攻击必须近距离获取电磁信息的局限性,针对没有电磁防护的密码设备提出一种基于相关性分析的远场攻击方法.使用微控制器运行高级加密标准算法,使用天线在远场探测电磁信号,先对采集的电磁信号均值和滤波以减少噪声的影响,再使用相关性分析方法进行旁路攻击,在天线距离微控制器10 m处成功破解出完整的密钥.同时也对远场电磁旁路攻击中的频率和样本量做了深入研究,带有密钥信息的电磁旁路主要集中在一段频率范围内,而且随着样本量的增加密钥信息越明显,以此为基础结合密码芯片产生密钥信息泄露的机理,提出了改进的电磁旁路攻击方法.

Electromagnetic side channel attack is an effective method in side channel attack. In order to overcome the limitations of traditional electromagnetic side channel attacks that must be acquired at close distance, a far field attack method based on correlation analysis is proposed for cryptographic devices without electromagnetic protection. The microcontroller running the advanced encryption standard(AES) and the antenna detecting the signal in the far field were used in our experiment. Before perform the side channel attack, we take the average value and filter the collected signal to reduce the influence of noise. Successfully we crack all 16-byte keys at 10 m. At the same time, the frequency and sample size of the far field electromagnetic side channel attack are deeply studied. In fact, the electromagnetic side channel with key information mainly concentrates in a frequency range, and the the key information is more obvious with the increase of sample size. Based on this, an improved electromagnetic side channel attack method is proposed combining with the mechanism of key information leakage generated by cryptographic chips.