Protected ECC Implementations
Łukasz Chmielewski, Louiza Papachristodoulou · 2025
Elliptic curve cryptography (ECC) is broadly used in security products for digital signatures and for the establishment of a common secret key. This chapter considers various techniques for protecting implementations based on elliptic curve cryptosystems against side-channel and fault injection attacks. It provides a step-by-step approach of how to develop a secure ECC implementation against side-channel attacks and fault analysis. Scalar multiplication is the most critical operation in ECC implementations, since it manipulates the secret key. The straightforward implementation of scalar multiplication on an elliptic curve involves repeated doubling and addition operations, which is known as the double-and-add algorithm. The chapter also presents protected algorithms against more sophisticated attacks, such as conditional swap and address-bit side-channel attacks.