摘要 |
A method of decoding/encoding a content file is provided. The method of decoding a content file includes dividing an encoded content file into a plurality of data blocks, grouping the plurality of data blocks into a plurality of groups, generating a group content key for each of the plurality of groups, generating a plurality of block keys for the data blocks in each of the plurality of groups from the group content key generated for each of the plurality of groups, and decoding the plurality of data blocks using the plurality of block keys. |