Introduction to Masking
Ange Martinelli, Mélissa Rossi · 2025
In order to thwart the menace of passive side-channel attacks such as differential power analysis or templates attacks, the most deployed software countermeasure has been masking since its introduction in 1999. This chapter presents an overview of three prominent leakage models: probing model, random probing model, and noisy leakage model. In practice, masking is a costly countermeasure and efficiency matters are prominent. Thus, the vast majority of the masked schemes involve efficient recombination functions when composed of the most numerous operations of the cryptographic algorithm, often linear operations such as XOR, modular additions or multiplications by scalars. In practice, the two foremost maskings are Boolean masking and arithmetic masking. While Boolean and arithmetic masking are the most common choices, a lot of other operations are possible such as code-based masking and hybrid masking.