| 摘要 |
PROBLEM TO BE SOLVED: To make it difficult to decipher information by using plural kinds of encryption systems. SOLUTION: In this data communication equipment, an encryption system determining function part 2 previously sets what kind of encryption system is to be used in the case of transmission. A data link insertion data generating function part 3 inserts the previously set encryption system information into a data link, as a control signal. An encrypting function part 1 encrypts transmission data in accordance with the encryption system. A frame synchronization (FAS) inserting part 4 inserts the control signal in the encrypted transmission data, and transmits the data to which frame information is imparted. A frame synchronization (FAS) detecting function part 7 establishes frame synchronization from received encrypted data. A data link detecting function part 8 extracts information of the encryption system, where synchronization is established and data are encrypted. A decoding system selecting function part 9 selects a decoding system, on the basis of information of the encryption system. A decoding function part 10 performs decoding, using the selected system. |
