Patent ID: 8621593

Claim:
An electronic device comprising: circuitry configured to generate a secret key shared between the electronic device and another electronic device; output a first response request, which is transmitted to the another electronic device using Transmission Control Protocol (TCP), the first response request generated based on the secret key and a first random number; receive a first response message based on the first response request, the first response message transmitted from the another electronic device and including first authentication data based on the secret key and the first random number; output a second response request using TCP, which is transmitted to the another electronic device after receiving the first response message, the second response request generated based on the secret key and a second random number; count a time elapsed from transmitting the second response request; receive a second response message based on the second response request, the second response message transmitted from the another electronic device and including second authentication data generated at the another electronic device based on the secret key and the second random number; compare the second authentication data included in the second response message with expected authentication information generated by the electronic device based on the secret key; and determine that authentication of the another electronic device has failed when the comparison result indicates that the second authentication data and the expected authentication data do not match or when a predetermined time elapsed from transmitting the second response request expires before the second response message is received.