System, program, and nonvolatile storage medium

A non-transitory computer-readable storage medium storing a program which, when executed on a terminal, causes the terminal to execute:

• in a case of uploading data to a node,
• selecting one node;
• encrypting a predetermined element included in data to be uploaded;
• and
• uploading the data including the encrypted predetermined element to the selected one node, and
• in a case of downloading data from a node,
• the selecting one node;
• downloading data from the selected one node;
• and
• decrypting a predetermined element included in the downloaded data, wherein
• the selecting one node includes:
• requesting two or more pieces of node identification information from the server, the two or more pieces of node identification information being selected based on geographical proximity from among a plurality of pieces of node identification information stored in the server;
• receiving the two or more pieces of node identification information from the server;
• requesting three or more pieces of node identification information from the server, the three or more pieces of node identification information being selected at random from among the plurality of pieces of node identification information stored in the server;
• receiving the three or more pieces of node identification information from the server;
• requesting inspection data from each of a total of five or more nodes received from the server;
• receiving the inspection data from each of the total of five or more nodes;
• and
• determining whether a majority of the total of five or more nodes store the same inspection data and at least one of nodes identified by the two or more pieces of node identification information selected based on geographical proximity is included in the majority of the nodes storing the same inspection data, and when the at least one of nodes is included, selecting one node included in the majority of the nodes storing the same inspection data and identified by one of the pieces of node identification information selected based on geographical proximity.

A non-transitory computer-readable storage medium storing a program which, when executed by a node, causes the node to execute:

• selecting one node;
• and
• updating data stored in the own node by using data stored in the selected one node, wherein
• the selecting one node includes:
• requesting two or more pieces of node identification information from the server, the two or more pieces of node identification information being selected based on geographical proximity from among a plurality of pieces of node identification information stored in the server;
• receiving the two or more pieces of node identification information from the server;
• requesting three or more pieces of node identification information from the server, the three or more pieces of node identification information being selected at random from among the plurality of pieces of node identification information stored in the server;
• receiving the three or more pieces of node identification information from the server;
• requesting inspection data from each of a total of five or more nodes received from the server;
• receiving the inspection data from each of the total of five or more nodes;
• and
• determining whether a majority of the total of five or more nodes store the same inspection data and at least one of nodes identified by the two or more pieces of node identification information selected based on geographical proximity is included in the majority of the nodes storing the same inspection data, and when the at least one of nodes is included, selecting one node included in the majority of the nodes storing the same inspection data and identified by one of the pieces of node identification information selected based on geographical proximity.

A non-transitory computer-readable storage medium storing a program which, when executed on a computer, causes the computer to execute:

• requesting two or more pieces of node identification information from a server, the two or more pieces of node identification information being selected based on geographical proximity from among a plurality of pieces of node identification information stored in the server;
• receiving the two or more pieces of node identification information from the server;
• requesting three or more pieces of node identification information from the server, the three or more pieces of node identification information being selected at random from among the plurality of pieces of node identification information stored in the server;
• receiving the three or more pieces of node identification information from the server;
• requesting inspection data from each of a total of five or more nodes received from the server;
• receiving the inspection data from each of the total of five or more nodes;
• and
• determining whether a majority of the total of five or more nodes store the same inspection data and at least one of nodes identified by the two or more pieces of node identification information selected based on geographical proximity is included in the majority of the nodes storing the same inspection data, and when the at least one of nodes is included, selecting one node included in the majority of the nodes storing the same inspection data and identified by one of the pieces of node identification information selected based on geographical proximity.