首页>
外国专利>
Key management device/method/program, recording medium, reproducing device/method, recording device, and computer-readable, second recording medium storing the key management program for copyright protection
Key management device/method/program, recording medium, reproducing device/method, recording device, and computer-readable, second recording medium storing the key management program for copyright protection
The key management device manages keys respectively arranged on nodes forming an N-layer tree structure. Each group of keys composed of a key on the Nth layer and all its superordinate keys is assigned to a different reproducing device. Upon receipt of information designating a key group, the key selecting unit invalidates each key in the key group, and selects non-invalid keys immediately subordinate to each invalid key. The content encrypting unit encrypts a content using a content key. The ciphertext generating unit generates ciphertexts by encrypting the content key using each selected key. The selected key list generating unit generates a list of the selected keys used to encrypt the content key. The key management device records the encrypted data and the ciphertexts in a recording medium. The reproducing devices reads the recording medium, obtains the content key by decrypting s ciphertext using a key identified in the list.
展开▼
机译:密钥管理设备管理分别布置在形成N层树结构的节点上的密钥。由 N I> th Sup>层上的键及其所有上级键组成的每组键都分配给不同的再现设备。在接收到指定密钥组的信息时,密钥选择单元使密钥组中的每个密钥无效,并选择紧随每个无效密钥的非无效密钥。内容加密单元使用内容密钥来加密内容。密文生成单元通过使用每个选择的密钥对内容密钥进行加密来生成密文。所选密钥列表生成单元生成用于加密内容密钥的所选密钥的列表。密钥管理设备在记录介质中记录加密的数据和密文。再现设备读取记录介质,通过使用列表中标识的密钥对密文进行解密来获得内容密钥。
展开▼