This procedure is performed sixteen times. Kn, which is based on the key. Since this algorithm goes through sixteen iterations, Kn will be of length forty eight. The calculation of Kn is another operation where one looks in the table provided by the government. First, however, notice that R is of thirty two bit length and K is forty eight bits long.
R is expanded to forty eight bits using another table.
The result of this addition is broken into eight six bit strings. One enters into another table that gives the primitive function Sn. There is one S function for each six bit block. The result of entering into these S functions is a thirty two bit string. After sixteen iterations we should have L16 and R16.