Methods for increasing the data security of implementations of cryptographic algorithms

摘要

The invention relates to a method for increasing the data security of implementations of cryptographic algorithms, preferably of implementations of the DES algorithm or of variants of the DES algorithm. It is based on the task of specifying a method by which data security is increased with regard to an attack carried out in the manner of differential power analysis. According to the invention, the security of a system comprising a central processing unit (CPU) and a memory and implemented with the implementation of the algorithm and implemented using the algorithm is increased in that the Hamming weight which directly influences the power consumption of the system and which in each case via the data bus between the CPU and the memory data blocks to be transmitted are modified in a clearly reversible manner at least before the transmission in one of the transmission directions - from the CPU to the memory or from the memory to the CPU.