APPARATUS AND METHOD FOR ENCODING HIERARCHICALLY USING UNIDIRECTIONAL FUNCTION

摘要

PURPOSE: An apparatus and a method for encoding hierarchically using unidirectional function are provided to encode data having hierarchical information efficiently. CONSTITUTION: The Nth hierarchical key generation part(62) generates the Nth hierarchical key. The (N+1)th hierarchical key generation part(63) generates the (N+1)th hierarchical key by inserting the Nth hierarchical key to an unidirectional function. The Nth hierarchical data encoding part(69) encodes the Nth hierarchical data using the Nth hierarchical key. And the (N+1)th hierarchical data encoding part(611) encodes the (N+1)th hierarchical data using the (N+1)th hierarchical key.