FIELD: physics, computer engineering.
SUBSTANCE: invention is related to systems for data processing and in particular, to methods and devices for protection and devices for protection in data processing system. Method and device for protection of transmissions. Every user is provided with registration key. Updated long-term broadcasting key is coded with the help of registration key and is periodically represented to user. Updated short-term key is coded with the help of broadcasting key and is periodically represented to user. Broadcasts are then coded with help of short-term key, where user decodes broadcasting message with the help of short-term key. One version of realisation provides coding of channel level content. The other version of realisation provides for continuous coding.
EFFECT: increased noise immunity of data transmission.
51 cl, 14 dwg
