Zyuzya O. Methods for data protection from reconstruction by power analysis in terminal components of computer systems

Thesis is dedicated to a problem of protection the keys of cryptographic algorithms during its implementation on microcontrollers and smart cards from power analysis. The analysis of cryptographic algorithm's structures and basic operations with respect to the requirement of their polymorphic implementation is performed. It has been shown that for symmetric algorithms, such DES, Rijndael and GOST 28.147-89 there are two levels of polymorphic implementation: level of blocks of message computing and level of iterations several block processing. By theoretical way has been proved that Rijndael polymorphic implementation of operations is bounded only to two consecutive iterations of algorithm. The techniques for Rijndael and GOSN 28.147-89 polymorphic implementation based on random choosing of program sections sequences have been proposed and investigated. The proposed method for Rijndael stochastically polymorphic implementation provides the variation of moment operation time bounded by 85% from one iteration processing time. It has been shown that exponent of modular exponentiation which is secret key of RSA, El-Gamal and DSA can be reconstruction by timing power analysis. As countermeasure the technology for polymorphic implementation modular exponentiation has been worked out. Proposed method does not conditional operators use and proved the polymorphic implementation of modular multiplications at a sacrifice of storage in memory operands for those operations The application of the proposed method enables a significant increase in the reliability of data security in networked devices.