| 摘要 |
PURPOSE:To prevent a person who does not know a cipher from updating a data, or from reading the data, by searching a key part by using an enciphered retrieval data. CONSTITUTION:Write of the first record 54-the n-th record 56 is performed by a WRITE CKD command, respectively, and read or updating of a data part of the record is performed by a READ D or write D command which is issued subsequently to a SEARCH K command for executing a retrieval of a key part, respectively. A data transfer controlling circuit 203 executes a comparison of a decoded retrieval data sent from a decoding circuit 202 through a signal line 223, and a key part which is read from a selected storage device, and sent through a subordinate device interface circuit 204 and a signal line 224. When the contents of the decoded retrieval data and the key part coincide, an execution of the WRITE D or READ D command which is chained by the SEARCH K command is permitted, the contents of the data part is updated or read. |
