FIELD: engineering of devices for recording and reproducing information.
SUBSTANCE: in tree-like system of keys distribution renewed data of main key and carrier key are transferred together with key renewal block. Key renewal block is such, that each one of devices, connected as leaves of tree-like structure, has leaf key and limited hub key. Concrete key renewal block may be generated for group, identified by certain hub, and assigned to group for limiting device, for which it is possible to renew key. Any device not belonging to group can not decode the key, due to that it is possible to provide protection of key distribution. In particular, in a system using main key with controlled generation, it is possible to distribute main key renewed by means of key renewal block.
EFFECT: minimized data distribution load.
9 cl, 55 dwg
