| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a secret communication system for making cipher be hardly decrypted by spectrum analysis and preventing deterioration in transmission performance from being generated, in principle.SOLUTION: A data transmitter 10 includes: an orthogonal modulator 11 for performing orthogonal conversion on a transmission data stream 15 to obtain a modulation signal; a transmission encryption key generator 12 for generating a data pattern previously agreed with a data receiver 20, as a transmission encryption key; and a group delay distortion generator 13 for encrypting the modulation signal by adding group delay distortion to the modulation signal to obtain an encryption modulation signal, and transmitting, through a transmission channel 30, the encryption modulation signal. The data receiver 20 includes: a reception encryption key generator 22 for generating, as a reception decryption key, the same data pattern as the data pattern used for generating the group delay distortion on the data transmitter 10 side; and an orthogonal demodulator 21 for performing demodulation on a modulation signal obtained by performing decryption by equalizing the encryption modulation signal received from the data transmitter 10, to obtain an original data stream to be output as a reception data stream 25.</p> |
