| 摘要 |
PURPOSE:To protect data written into an IC memory card. CONSTITUTION:At the time of writing data into the IC memory card 11, first key data K1 is loaded on a pattern generator 15 and pattern data P is sequentially generated. A ciphering part 13a executes ciphering calculation by using data D and pattern data P, executes address conversion calculation by using second key data K2 and a data storage destination address A2, and writes ciphered data D' into the position of the IC memory card 11, which an obtained address A2' shows. At the time of reading data from the IC memory card 11, first key data K1 is loaded on the pattern generator 15 and a pattern data string P similar to that at the time of writing data is generated. A decoding part 13b executes address conversion calculation by using the data read address A2 and second key data K2 and executes decoding calculation by using data D' which is read from the position of the IC memory card 11 shown by obtained address A2' and pattern data P. |
