METHOD FOR CRYPTOGRAPHIC TRANSFORMATION WITH SIMULTANEOUS GENERATION OF A DERIVED ENCRYPTION KEY Russian patent published in 2022 - IPC H04L9/06 

FIELD: cryptography.

SUBSTANCE: invention relates to methods for cryptographic transformation with simultaneous generation of a derived encryption key. During the cryptographic transformation of digital data blocks, digital data is divided into blocks. The data blocks to be encrypted are grouped into several data blocks and the encryption of a group of data blocks is carried out jointly. When encrypting, an initialization vector block is formed and used as the first block in a group of encrypted blocks. When decrypting, the result of decrypting the first block of data is not used. Additionally, encryption is carried out with the development of a chain of derived encryption keys. In this case, when encrypting for the first group of encrypted data blocks, the keys formed from the cryptographic key are used as iterative keys for the first data block in the group. When encrypting subsequent groups of data blocks, the results of encrypting the last data block in the previous group of data blocks are used as iterative keys for the first data block in the group.

EFFECT: facilitating the processes of synchronous generation of a derived encryption key on the encrypting and decrypting sides.

1 cl, 4 dwg, 4 tbl