BLOCKCHAIN SYSTEM, PROGRAM, AND NETWORK CONNECTION DEVICE

A block chain system includes a network connection apparatus and a plurality of nodes, and includes a node information managing unit, a network connection apparatus information managing unit, a block chain network information managing unit configured to manage information related to a block chain network, a block chain node updating unit configured to update block chain nodes in response to a change in information related to the plurality of nodes, a propagating unit configured to propagate, to the block chain nodes, information that is input in the block chain network for recording, and a recording unit configured to record the information in the block chain network, in a case where agreement is achieved with respect to the information that is input.