Class Kuznyechik

Kuznyechik core class

Decrypts single block of data using Kuznyechik encryption algorithm.

Encrypts single block of data using Kuznyechik encryption algorithm.

Returns round keys

Performs Galois Field (GF(2)) multiplication.

This method multiplies two bytes in the Galois Field using bitwise operations, applying the irreducible polynomial x^8 + x^7 + x^6 + x + 1 for modular reduction.

F-transformation aka XSLX-algorithm

Performs a key transformation using a series of linear and substitution transformations.

L-transformation

Performs a linear transformation on the input block by repeatedly applying the R-transformation a fixed number of times (equal to the block size).

Lrev-transformation

Performs a linear transformation on the input block by repeatedly applying the Rrev-transformation a fixed number of times (equal to the block size).

R-transformation

Performs a linear transformation on the input block by cyclically shifting bytes and applying Galois Field multiplication with a predefined linear transformation matrix (L).

Rrev-transformation

Performs a linear transformation on the input block by applying Galois Field multiplication with a predefined linear transformation matrix (L) and cyclically shifting bytes.

S-transformation.

The S function is a regular substitution function. Each byte of the input sequence is replaced by the corresponding byte from the PI substitution table.

Srev-transformation

The Srev function is a regular substitution function. Each byte of the input sequence is replaced by the corresponding byte from the PI_REV substitution table.

X-transformation.

The input of the X function is two sequences, and the output of the function is the XOR of these two sequences.