2001-01-25

Steak - Main Function

The main function of Steak processes a 32-bit DWORD of dynamic key data at a time. It's core is a Matrix Table transform, which consists of a distortion of the Maximum Distance Separable mapping of TwoFish. This mapping has been altered to make the distribution of the cipher output as close to randomness as possible. The columns of the MDS bitwise 32x32-matrix has been permuted, and the input is permuted before the S-Boxes are entered. This process is preceded by a static whitening and succeded by a dynamic. Finally, the output is rotated left by 4 before the function returns.

Note that the Main Function is a bijective function of A, of PV and of V, given that the other two respective parameters are constant.