| 摘要 |
PURPOSE:To attain an inexpensive ciphering system by providing a ciphering function in plural MODEMs and applying ciphering control under the control of the MODEMs. CONSTITUTION:A transmission/conversion section consists of a synchronizing signal 'syn' detection circuit, a switch (SX) deciding whether or not data are scrambled, ciphered or nothing is processed, a cipher selection circuit, a scrambler circuit applying a definite scrambling, a ciphering circuit and a modulation circuit modulating a digital signal into an analog signal and sending the result. If a ciphering request signal (CYP) is set, the ciphering circuit is selected by using a cipher selection signal (CEn) to cipher the pre-sent data and send the result. Thus, the titled converter is economized by integrating the ciphering device and the MODEM.
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