An optical connection device includes: a substrate; an optical waveguide provided in the substrate; and plural optical connection ports provided in the optical waveguide and having at least one of a light output port and a light input port, the light output port outputting light to the optical waveguide, the light input port receiving light from the optical waveguide, and is characterized by further including an arithmetic circuit for, using a key, selectively decoding an optical signal which has been coded in such a manner that it is decoded only at a light input port that is given a key for decoding and which has been outputted from a light output port to the optical waveguide to be received at the light input port.