초록 ▼

A privacy communication system in which increased security is provided in the scrambling of speech signals. Input speech is separated into a high frequency band and a low frequency band, and each band is time scrambled independently and recombined prior to transmission. Additional security is obtain

A privacy communication system in which increased security is provided in the scrambling of speech signals. Input speech is separated into a high frequency band and a low frequency band, and each band is time scrambled independently and recombined prior to transmission. Additional security is obtained with randomly selected segments of the scrambled speech being reversed in time. Further randomizing of the pseudorandom sequence which controls the scrambling operation is also provided, as well as simplified computing of delay times for the descrambling operation.

대표청구항 ▼

A privacy communication system in which segments of data are randomly shifted in time prior to transmission, comprising filter means for separating data signals into respective high frequency and low frequency channels; encoder means, coupled to said filter means, for encoding the data signals in ea

A privacy communication system in which segments of data are randomly shifted in time prior to transmission, comprising filter means for separating data signals into respective high frequency and low frequency channels; encoder means, coupled to said filter means, for encoding the data signals in each channel into digital form; first and second memory means connected to said filter means for storing said respective channels of data signals in segments of predetermined length; first memory address means for generating address signals to address the storage locations in each segment of said first and second memory means for storage and retrieval of the data signals of each segment; second memory address means for generating first and second random sequences of segment address signals to control the sequence of segment selection in said respective first and second memory means for storage and retrieval of data in random manner; decoder means for decoding the data signals retrieved from said first and second memory means; and summing means, coupled to said decoder means, for adding the first and second channels of data signals retrieved from said first and second memory means prior to transmission.