| 摘要 |
PROBLEM TO BE SOLVED: To provide a communication system, communication method, and communication program, capable of surely preventing input data input to a communication terminal from being leaked.SOLUTION: The communication system includes a communication terminal having a terminal input unit, and a center device communicable with the communication terminal. The center device includes: a center key generation unit for generating a public key and a secret key in timing when the communication terminal starts to be used by a user; a center communication unit for transmitting the public key to the communication terminal; and a center storage unit for storing the secret key. The communication terminal includes: a terminal communication unit for receiving the public key from the center device; a terminal key generation unit for generating a common key; an encryption unit for encrypting input data input from the terminal input unit by using the common key to define the encrypted data as encryption data and encrypting the common key by using the public key to define the encrypted key as an encryption key; and a terminal storage unit for storing the public key, the encryption data, and the encryption key associated with the encryption data. |
