To load different random initial values on random number generating circuits of plural communication terminal and to reduce the possibility that generated random numbers coincide with each other.

This device 1 is comprised of a terminal circuit 4, a random number generating circuit 5, a memory circuit 6, a MAC(Memory Access Control) circuit 7, and a switch circuit 8. Here, when a housing device 3 is able to house N-pieces of communication terminal devices and the switch circuit 8 permits to set 8 kinds of numerical values, the random number initial values of the random number generating circuit 5 are stored in N-pieces of addresses of the memory circuit 6, and the random initial values read from the addresses of the memory circuit 6 corresponding to the set values of the switch circuit 8 are loaded into the random number generating circuit 5.