초록 ▼

A system and method are disclosed for encrypting a voice signal. The input signal is filtered to provide a signal in a first path with components in a higher frequency band and a signal in a second path with components in a lower frequency band. Analog-to-digital conversion is carried out at a rate

A system and method are disclosed for encrypting a voice signal. The input signal is filtered to provide a signal in a first path with components in a higher frequency band and a signal in a second path with components in a lower frequency band. Analog-to-digital conversion is carried out at a rate such that the frequency composition of the higher frequency path is inverted and shifted into the lower frequency band. Signals from the two paths are intermixed and converted to analog form at a rate greater than twice the rate of analog-to-digital conversion, so as to provide a randomized sequence of time segments of signals from the two paths, interspersed with gaps.

대표청구항 ▼

A system for encrypting an analog input signal, comprising: means for filtering said input signal to provide a signal in a first path, having frequency components in a higher frequency band, and a signal in a second path having frequency components in a lower frequency band; means for deriving digit

A system for encrypting an analog input signal, comprising: means for filtering said input signal to provide a signal in a first path, having frequency components in a higher frequency band, and a signal in a second path having frequency components in a lower frequency band; means for deriving digital samples from the signal in the first path at a first rate and from the signal in the second path at the same rate, and for inverting the frequency composition in said first path so that frequency components which were at higher frequencies before inversion are at lower frequencies after inversion and components which were at lower frequencies are at higher frequencies, and for shifting the higher band frequency components in said first path to lie in said lower band; and means for intermixing segments of the samples from said first and second paths and converting to analog form at a rate greater than twice said first rate to provide a sequence of rearranged, randomized time segments of signals from said first and second paths, including means for interspersing said segments with gaps.