| 摘要 |
PROBLEM TO BE SOLVED: To allow a ciphering key check device to discriminate a decoding state in a short time by providing the ciphering key check device that processes data received by a terminal equipment into a plain text, decodes the text so as to check a ciphering key, decodes the data processed into a plain text in the unit of plural lines. SOLUTION: A control section 6 sets a decoding mode of a data processing section 4 to a block mode. Then the control section 6 instructs decoding of 50 lines to a processing section 4 and when decoding is executed, the decoding error is checked. Then the control section 6 checks whether or not a code RTC to be added to an end of compressed code data is in existence in the decoded 50lines and discriminates that the ciphering key of the transmitter is coincident with a ciphering key for a plain text by the receiver side when the code is detected. When the processing section 4 executes the decoding of succeeding 50-lines, the control section 6 checks whether or not any decoding error is in existence. When decoding of 1k byte is finished, the control section 6 discriminates that the data processed into a plain text are decoded in the unit of plural lines. |
