Summary. In this article described main types of SCA, their particularity and how they can be applied to modern, wide-used cryptosystems to break their security.

Keywords: SCA, encryption algorithm, hardware encryption, cryptosystem, side channel analysis, information security.

Summary. This article describes the modification of the RSA encryption algorithm using the Chinese remainder theorem, as well as the impact of the implementation of encryption using Chinese remainder theorem on the behavior of cryptosystem.

Keywords: RSA, encryption algorithm, digital signature, CRT, Chinese remainder theorem.