. . . "the key generator of the invention; FIG. 5 is a diagram showing non-linear distribution of the PN word sequence of FIG. 4 after processing in a data security device chip of the invention; FIGS. 6A and 6B are a general flow diagram of the keyboard entry routine; FIGS. 7A through 7NN are detailed flow diagrams of the keyboard entry routine; FIG. 8 is a flow diagram of the general data entry/edit sch" .