| 摘要 |
<p>PROBLEM TO BE SOLVED: To achieve the downsizing and cost reduction of a radio tag while securing security.SOLUTION: A radio tag 20 transmits a sequence number stored in a memory part 24 whose value is updated each time data are written in the memory part 24 to a reader/writer 10. The reader/writer 10 generates first encrypted data by using a value based on the sequence number and data to be written, and transmits the first encrypted data to the radio tag 20. The radio tag 20 generates second encrypted data by using a value based on the sequence number and the data to be written, and when the first encrypted data are coincident with the second encrypted data, writes the data to be written in the memory part 24, and updates the sequence number. This invention may be applied to, for example, communication equipment for performing proximity communication.</p> |
