Patent ID: 7724900
Filing Date: 2010-05-25
Classification: H04L

Abstract:
1. An information processing apparatus configured to decrypt, using meta data, encrypted data obtained by encrypting stream data including a plurality of successive units of data according to a first encryption method in which, when the stream data is sequentially encrypted on a unit-by-unit basis, each of a plurality of encryption keys, used for encrypting a corresponding one of the units of data, is updated on the basis of a predetermined rule, the meta data including the plurality of the encryption keys used for encrypting the stream data and update information for identifying update timings of the plurality of encryption keys, the apparatus comprising: a decrypter configured to acquire the encrypted data and decrypt each of the encrypted units of data in the encrypted data using a decryption key corresponding to the encryption key used for encrypting the unit of data among the plurality of encryption keys; and a meta data acquirer configured to acquire the meta data, to generate each of the plurality of decryption keys corresponding to one of the plurality of encryption keys included in the meta data, and to deliver the corresponding one of the plurality of decryption keys to the decrypter in accordance with the update information included in the meta data; wherein the plurality of encryption key are encrypted according to a second encryption method and the meta data acquirer includes,