| 摘要 |
PURPOSE:To prevent common symbols and specific symbols from becoming difficult to know and being abused by ciphering the common and specific symbols to be exchanged to acquire the access permission of a memory provided on the data carrier and converting them into another symbol string to transmit them. CONSTITUTION:A reader/writer 10 is provided with a control section 11, transmission and reception section 12, common symbol ciphering section 13, common symbol transmission section 14, specific symbol reading section 15, specific symbol decoding section 16, specific symbol ciphering section 17, and specific symbol transmission section 18. A data carrier 20 is provided with a nonvolatile memory 21 such as E<2>PROM, control section 22, transmission and reception section 23, common symbol decoding section 24, common symbol collation section 25, specific symbol ciphering section 26, specific symbol decoding section 27, and specific symbol collation section 28. With the use of the common and specific symbols, the acquisition processing of the access permission of the data carrier from the reader/writer is performed. |
