An intermediate entity can generate a necessary credential to allow two other entities to bypass the intermediate entity when establishing communications between two other entities in a computing system represented by either a directed or an undirected graph. In at least some embodiments, a non-volatile memory device can include a cross-point array having resistive memory elements disposed among word lines and subsets of bit lines, and an access signal generator. An active layer is disposed on the gate insulating layer. The second switching parts 3A-3D each comprise: a planar waveguide device 9 in which coupling optical waveguides 10a-10d and an output optical waveguide 11 are provided; and reflection mirrors 13a-13d for reflecting a light signal incident from the respective coupling optical waveguides 10a-10d to the output optical waveguide 11.