FIELD: technologies for preventing interception of data.
SUBSTANCE: transferred signal is concealed via adding noises to communication line in speech frequency range with linear addition of speech data signal with noise signal of higher level. Concealment is removed via adaptive filtration of received signal with compensation of noise component and separation of data component. Addition of noises to communication line is performed from the side of sensor. Noise signal during addition of noises and adaptive filtration is formed of a sum of counts of several noise series with nonevent sizes via their random querying. At the beginning of each communication session a signal is sent to side of receiver, characterizing order of querying of series, and starting signal, providing for synchronism of noises addition and filtering processes. All operations are performed by means of microprocessors, mounted on both sides of communication line, dependently of loaded software providing for change of direction of transmission and protection of speech data signal. Invention allows to simplify protection while providing for absolute confidentiality of transmitted data.
EFFECT: higher reliability.
6 cl, 4 dwg
Authors
Dates
2005-03-27—Published
2004-06-03—Filed