Спосіб блочного шифрування електронної інформації

Abstract

The proposed method of block-to-block coding of data transmitted by electronic facilities consists in forming the encryption key, which has a fixed length and consists of four n-bit key elements K1, K2, K3, and K4, dividing the input data block into two n-bit constituent data blocks A and B, performing the encryption procedure by transforming the constituent data blocks according to the encryption key and performing operations of modulo 2 addition with respect to the data block and the encryption key and operations of cyclical shift with respect to the constituent data block. As the encryption key for the first data block, a random number is used. For each consequent data block, the encryption key is modified, depending on the current data block, by operations of modulo 2 addition and operations of cyclical shift that are performed with respect the encryption key depending on the constituent data block. The cyclical shift is performed by the value that is equal to the value of two bytes of the control operand added by modulo 2. The present invention provides a possibility to encrypt data with reduced number of operations.