Patent ID: 6697945
Filing Date: 2004-02-24
Classification: G06F,G11B,H04L

Abstract:
A data transmitting apparatus wherein data is transmitted after predetermined processing based upon said apparatus' own ID code and an ID code received from partner apparatus has been carried out, said apparatus comprising:a signal receiving means for receiving a signal from a partner apparatus; a signal transmitting means for transmitting a signal to a partner apparatus; and a signal encrypting means for carrying out predetermined encryption on a signal to be transmitted, wherein said signal encrypting means examines information indicating a signal transmitting source received from said signal receiving means and, if encrypted text generated by encrypting a session key is found already transmitted to said signal transmitting source, said encrypted text is not transmitted again to said signal transmitting source; whereby said ID code received from said partner apparatus is stored in a storage means while said session key is used for a current session, and said ID code received from said partner apparatus is deleted from said storage means when another session key is used for a next session; and whereby said session key is encrypted according to a license key that is generated by concatenating said ID code received from said partner apparatus with a service key unique to the data to be transmitted and applying a hash function to the concatenation.