Explore a way of improving the computational efficiency of the block in SCILAB

SCILAB as an open source software is now becoming more and more popular among students, engineers, and scientists. Its powerful computation and simulation function provide a great convenience for its users. But because of people's unfamiliarity about its internal formalism, there still come out some problems when people using it. This paper, based on the construction of the DES (Data Encryption Standard) System in SCICOS or XCOS, mainly studied the problem about the block's low computational efficiency which is because of the ignoring of the formalism of block's compute function, and provided a solution of improving the block's computational efficiency.