Mitigating the Side Channel Power Analysis Attacks using New Variable Mapping Substitution Technique

Side-channel attack has been a real threat against many cryptographic embedded systems. In this attack, the internal data is retrieved directly by analyzing the power magnitude according to the fact that there is a considerable difference in power when manipulating 0’s and 1’s. A commonly used algorithmic countermeasures incur large execution delay and resources overheads. In this paper, a novel technique using Variable Mapping Substitution (VMS) is proposed for mitigating side channel power analysis attack against Advanced Encryption Standard (AES). VMS-AES is a novel AES-like algorithm which uses Linear Feedback Shift Register (LFSR) to generate the required parameters used to remap the values of substitution box (S-box) randomly to another location depending on a secret key. This remapping also keeps the same good linear and differential properties of the AES S-box. VMS-AES algorithm can be easily deployed in most embedded applications because no architectural change is needed and only software modifications are performed. In our proposal, chipwisperer side channel attack analysis tool is used to verify the effectiveness of the proposed algorithm. Also VMS-AES with different number of rounds is evaluated using three methods: NIST statistical suite tests, correlation coefficient analysis, and cryptographic parameters evaluation to study the effects of this change upon the AES security