Implementation of a Boolean Masking Scheme for the SCREAM Cipher
William Diehl, Kris Gaj · 2016
Masking is a proven countermeasure to protect physical cryptographic implementations against power analysis side-channel attacks, such as differential power analysis (DPA). Boolean masking is one of several types of masking schemes that can be added to a cipher to increase its security. However, implementing a secure and efficient Boolean masking scheme across all components of a cipher, including non-linear transformations, can be challenging. In this research, a 1st order Boolean masking scheme is applied to the SCREAM authenticated cipher, a CAESAR Round Two candidate. The non-masked and masked versions of the full authenticated cipher are implemented in the Virtex-6 FPGA and compared in terms of throughput, area, and throughput-to-area (T/A) ratio. The SCREAM block cipher is then compared to a masked version of AES to determine the relative costs of masking among the two ciphers. The results show that the T/A ratio of the masked SCREAM full authenticated cipher is only 50% of the T/A ratio of the non-masked version, and that the masking cost of the SCREAM block cipher is roughly equal to that of an equivalently-masked version of the AES block cipher.