针对 LBlock 算法 BBC 编码方式的功耗分析与防护^*

With the rapid development of the RFID chip, wireless sensor networks and other micro computing equipment, lightweight block ciphers are widely used and their security attracted more and more attention. Power Analysis, which brings huge threats to Cipher Chips, is a common technique in side channel analysis. This paper analyses LBlock cipher algorithm in intelligent IC cards, discusses the security of Bitwisely Balanced encoding (short for BBC) and finds some security flaw under the Power Analysis attack. First, through the analysis of the LBlock cryptography algorithm in BBC, we found effective attack position and through acquiring the trace that in that position to reconstruct the templates according to the hamming weight model structure, use the template attack to recover the key step by step. Second, through the experiment, this paper proves the effectiveness of the template attack methods proposed in this paper. In addition, this paper proposes a kind of mask level protection method of side channel attack about LBlock algorithm. Experiments show that this method can effectively resist first-order power analysis attack. Then we compared masked and unmasked LBlock algorithm with respect to three indicators: program file size, storage and encryption time. The results show that these three indicators are in a reasonable range.