Masking schemes are widely used in practice to defeat side-channel attacks, which exploit the power consumption of devices. At the same time a large body of recent theoretical works study feasibility of computation in the presence of leakage and attempts to provide a formal security analysis of the masking countermeasure. In this talk, we will review some recent advances in the formal security analysis of masking schemes and present efficient ways how to apply the masking countermeasure at smart card level.