Communication device and communication system

A communication system comprising:

• a wireless terminal;
• and
• a communication device communicating position information indicative of a position of the communication device with the wireless terminal,
• wherein the communication device includes
• a first storage section configured to store the position information of the communication device, and a certificate to guarantee correctness of the position information, the certificate being issued upon the position information being authenticated,
• a sending section configured to send the position information and the certificate, and
• a control section configured to control the sending section so that the position information stored in the first storage section is sent to the wireless terminal along with the certificate,
• wherein the wireless terminal includes
• a second storage section configured to store a decryption key to decrypt the certificate, the decryption key being issued along with the certificate,
• a receiving section configured to receive the position information from the communication device, and the certificate, and
• a decryption section configured to decrypt the certificate received by the receiving section, with the decryption key stored in the second storage section.