COMMUNICATION SYSTEM, FIRST COMMUNICATION DEVICE, SECOND COMMUNICATION DEVICE, METHOD, COMPUTER DEVICE, AND COMPUTER PROGRAM

摘要

PROBLEM TO BE SOLVED: To provide a technology for sharing shared data safely and easily with two communication devices performing encrypted communication.SOLUTION: A first communication device encrypts shared data and sets the data as first encrypted shared data (S503) and transmits the data to a second communication device (S504). The second communication device receives the data (S601), further encrypts the first encrypted shared data, sets the data as second first encrypted shared data (S602), and transmits the data to the first communication device (S603). The first communication device receives the data (S505), performs inverse conversion of the encryption that has been performed by the first communication device on the second first encrypted shared data (S506) and sets the data as second encrypted shared data, and transmits the data to the second communication device (S507). The second communication device receives the data (S604), and performs inverse conversion of the encryption that has been performed by the second communication device on the second encrypted shared data to return the data to the shared data.SELECTED DRAWING: Figure 5