Abstract: The present invention relates to the field of electric communication and computer engineering, and more particularly, to the field of cryptographic methods and devices for ciphering digital data. The method comprises dividing a block of data N?2 subblocks; converting these subblocks one after another by generating at least one binary vector according to the subblocks value and modifying the subblock using the binary vector. Novelty of the claimed method is in generating the binary vector at the subsequent step of sub-block conversion depending on the binary vector structure at the preceding step of subblock conversion. Novelty is also in generating two binary vectors and converting one of them by operation of cyclic shift on a number of bits equal to the value of the second binary vector. Further, novelty is in modifying one of the subblocks by applying to it a cyclic shifting operation on a number of bits equal to the current value of the binary vector.

Abstract: The invention relates to telecommunications and computer engineering, and especially to cryptographic methods and devices intended to encrypt numerical data. The inventive method comprises the steps of working out K≧data blocks containing P≧1 elements of the binary information code and of converting data blocks under control of an encryption key. The novelty of the system consists in that D≧1 binary vectors are additionally generated, that the data blocks are formed by linking the binary vectors to the corresponding elements of the binary information code, that the binary vectors are generated at random and pseudorandom, that they are linked to the corresponding elements of the binary information code, and that this linkage is based on the secret key.