A low-entropy first-degree secure provable masking scheme for resource-constrained devices

The trend in the protection against side-channel analysis is to be more secure with little consideration for the cost. However in small devices like RFID, traditional security solutions might be impractical due to limited availability of resources. Thus designers are often forced to use imperfect but low-cost security solutions. When implementing masking countermeasures on a low-resource device, designers are not only limited in memory or power but also lacks a high-throughput source of randomness. In this paper, we stick to a formal security notion (1st-degree security), but seek a low-cost countermeasure against side-channel attacks. The proposed countermeasure is based on masking but needs only one bit of random to resist first-degree attacks like correlation power analysis. Furthermore the implementation also resists side-channel collision attacks once the entropy of random is increased to 16 bits. We show that security can be obtained at extremely low overhead and with as few as a couple of random bytes. This is supported by an application on PRESENT which is provably masked at first-degree for performance overhead of only 1%. Side-channel laboratory evaluations are also provided to support our claim.