Patent ID: 7532876
Filing Date: 2009-05-12
Classification: H04L,H04W

Abstract:
1. A communication system comprising: a first information processing apparatus including a first operation input unit and configured to transmit an authentication request radio wave at a first transmission intensity after the first operation input unit is activated by a user; a second information processing apparatus including a second operation input unit and configured to receive the authentication request radio wave transmitted at the first transmission intensity, and transmit a response radio wave at the first transmission intensity after the second operation input unit is activated; the first information processing apparatus is configured to receive the response radio wave, judge that the second information processing apparatus is within a range of physical proximity based on a reception intensity of the received response radio wave being larger than a reception intensity set in advance which defines the range of physical proximity, and transmit a request for a product ID of the second information processing apparatus at a second radio transmission intensity that is lower than the first radio transmission intensity; the second information processing apparatus is further configured to receive the request for the product ID and transmit the product ID at the second radio transmission intensity; the first information processing apparatus is further configured to receive the product ID of the second information processing apparatus, generate a random number, create a first key from the random number and the received product ID of the second information processing apparatus, create a second key from the first key and the product ID of the second information processing apparatus, and transmit the random number to the second information processing apparatus at the second radio transmission intensity; the second information processing apparatus is further configured to receive the random number from the first information processing apparatus, create a third key from the product ID and the received random number, create a fourth key from the third key and the product ID, store the fourth key as a code for authentication, and transmit the fourth key to the first information processing apparatus at the second radio transmission intensity; the first information processing apparatus is further configured to receive the fourth key from the second information processing apparatus, determine if the received fourth key is identical to the second key, store an indication that the second information processing apparatus is authenticated based on a result of the determination, and transmit first data to the second information processing apparatus at the first radio transmission intensity based on the stored indication that the second information processing apparatus is authenticated; and the second information processing apparatus is further configured to receive the first data and transmit second data to the first information processing apparatus at the first radio transmission intensity based on the stored code for authentication.