Korkishko L. Methods and structures of masked arithmetic for information security systems devices

The thesis is devoted to solving actual scientific problem of development and research of methods and means of implementing the masked arithmetic, which can be used to build cryptographic devices with increased resistance to cryptographic engineering attacks based on analysis of power consumption. The methods for performing basic operations of cryptographic algorithms for masked data representation are proposed in this work. The list of considered operations are: logical operations of conjunction and disjunction, data inversion in fields GF(2N), table-based transformations, conversion of mask type for masked data. Developed methods for performing logical operations of conjunction and disjunction, data inversion in fields GF(2N) on the data in the masked representation are characterized by the ability to process data with any given number of masks. For method for conversion of mask type for masked data further developed a method of adding masked data modulo 2N. Due to this developed method allows one to convert masked presentation of data from arithmetic masking to logical masking and vice versa. For proposed method for table-based transformations of masked data, additional intermediate masking of agreed type of mask input was introduced. That allowed one to perform table-based transformations on input with either logical or arithmetic masking and get the result with the given masking type. Based on developed methods for operations on masked data, developed Verilog-models of structures for cryptographic operation units performing the above operations and cores of specialized hardware-based processor of symmetric block encryption algorithms mCrypton and GOST 28147-89, which process masked data with one logical mask and allow a creation of cryptographic processor with high resistance to attacks by analyzing the power consumption.