Patent ID: 7648075

Claim:
A data transmission-reception system comprising: a reader-writer; a first contactless IC chip, which is a data source; and a second contactless IC chip, which is a data destination and which is capable of communication with the first contactless IC chip via the reader-writer, wherein the first and second contactless IC chips each have data areas of the same applications in memories built therein, wherein the first contactless IC chip includes first generating means for performing authentication with the second contactless IC chip by the use of data encrypted with a key generated by combining keys allocated to the data areas in which data to be transferred is managed to generate a transfer key used for encrypting the data to be transferred; and transmitting means for encrypting the data to be transferred with the transfer key generated by the first generating means and transmitting the encrypted data to be transferred to the second contactless IC chip, and wherein the second contactless IC chip includes second generating means for performing authentication with the first contactless IC chip by the use of data encrypted with a key generated by combining keys allocated to the data areas in which the data to be transferred is managed and which have the same applications as the data areas in the first contactless IC chip to generate a transfer key equivalent to the one generated in the first contactless IC chip; and acquiring means for decrypting the data to be transferred, which is transferred from the first contactless IC chip and which is encrypted with the transfer key generated by the first generating means, with the transfer key generated by the second generating means to acquire the data to be transferred.