METHOD OF STREAM ENCRYPTION USING COMPOSITE KEY Russian patent published in 2024 - IPC H04L9/00 

FIELD: cryptography.

SUBSTANCE: in the stream encryption method, a state matrix is created by recording the numbers in order from 0 to 255, the auxiliary key matrix construction option is selected, the auxiliary key matrix is calculated, the resultant key matrix is calculated, converting the numerical values of the elements of the resultant matrix of the key into a binary number system corresponding to the table of ASCII symbols, plaintext characters are recorded using the ASCII character table, obtaining the value of the character X_i, which corresponds to the plaintext character recorded in the binary number system, modulo two summation of one byte of ASCII symbols of the resultant key matrix and one byte of symbols X_i, receiving the encrypted message Y_i, transmitting the encrypted message Y_i, several resultant key matrices are used, encryption coefficients are randomly selected to form a matrix, a preliminary key matrix is calculated, number of matrices to be used for encryption and elements for encryption, as well as the element from which encryption and the encryption step are selected are selected. Multilayer matrix is calculated. Encryption coefficients are transmitted to the information recipient.

EFFECT: enabling stream encryption using a composite key.

2 cl, 2 dwg, 1 tbl