A data transmission-reception system includes a reader-writer, a first contactless IC chip being a data source, and a second contactless IC chip being a data destination, capable of communication with the first contactless IC chip via the reader-writer. The first and second contactless IC chips each have data areas of the same applications in memories built therein. The first contactless IC chip includes first generating means for performing authentication by the use of data encrypted with a key generated by combination of keys to generate a transfer key and transmitting means for encrypting data to be transferred with the transfer key and transmitting the encrypted data. The second contactless IC chip includes second generating means for performing authentication by the use of data encrypted with a key generated by combination of keys to generate a transfer key and acquiring means for acquiring the data to be transferred.