Patent ID: 8605903

Claim:
A communication system uniquely identifying a communication partner within a predetermined coverage area and transmitting and receiving information in a predetermined protocol, the communication system comprising a device and an information processing apparatus with one performing wireless communication with the other within the predetermined coverage area, the device including: random number generating means for generating a random number; device encryption means for encrypting or decrypting information in accordance with a predetermined algorithm based on a predetermined key; device secret key storage means for storing a secret key, the secret key being used by the device encryption means for encryption and decryption, and being pre-shared with the information processing apparatus; communication ID transmitting means for transmitting to the information processing apparatus a response containing a communication ID, the communication ID uniquely identifying the information processing apparatus as a communication partner, and being an ID encrypted from the random number with the secret key by the device encryption means, the random number being generated by the random number generating means in response to a poll transmitted from the information processing apparatus; and device transmitting and receiving means for transmitting or receiving information to or from the information processing apparatus, the information being encrypted or decrypted by the device encryption means using as a key the random number generated by the random number generating means; and the information processing apparatus including: apparatus encryption means for encrypting or decrypting information in accordance with an algorithm predetermined based on a predetermined key; apparatus secret key storage means for storing a secret key, the secret key being used by the apparatus encryption means for encryption or decryption, and being pre-shared with the device; communication ID storage means for storing the communication ID contained in the response transmitted and then received from the device in response to the poll, the communication ID being as an identifier for uniquely identifying the device as a communication partner; random number acquisition means for acquiring the random number by decrypting the communication ID with the secret key with the apparatus encryption means; and apparatus transmitting and receiving means for transmitting or receiving information to or from the device, the information being encrypted or decrypted with the random number as a key acquired by the random number acquisition means with the apparatus encryption means, wherein the communication ID is transmitted to the information processing apparatus before the information processing apparatus transmits the information being encrypted with the random number.