| 摘要 |
1,062,721. Telegraphy. ANSTALT EUROPAISCHE HANDELSGESELLSCHAFT. Jan. 21, 1965 [Jan. 21, 19641, No. 2799/65. Heading H4P. In a ciphering system, when certain predetermined characters are generated by the ciphering, the corresponding input character is sent in clear and the ciphered output inhibited. The generation of other predetermined characters results in the output of the ciphering unit being fed back to the input for reciphering. In an embodiment 5-bit serial characters are converted to parallel form and feed a code converter which produces an output on a different line for each character. Normally a signal on any one input is switched in the ciphering unit, controlled by punched tape or by permutating wheels, to one of a corresponding number of outputs. These outputs feed a code converter which generates 5-bit signals. When any one of certain output lines is energized, however, a switching unit disconnects the output line and instead the energized input line is connected direct to the code converter, whereby the character is not ciphered. Certain other output lines from the ciphering unit are connected back to the input of the ciphering unit for reciphering so that, for example, the character " carriage return " cannot be transmitted. At the receiver, which is similar to the transmitter, an unciphered character is recognized by noticing which output line is energized when the character passes through the deciphering unit. When recognized, the deciphering unit is disconnected and the character passes direct to the output unit. |
