| 摘要 |
<p>A concept for digital content protection makes use of a storage medium comprising an encrypted data content, being encrypted using a data content key such that the data content key can be decrypted using a first cryptographic method, a first-method-encrypted version of the data content key, encrypted such that it can be decrypted using a first cryptographic method media key, a second-cryptographic-method encrypted data content key, which is an encrypted representation of the data content key or the first-method-encrypted data content key, encrypted such that the data content key or the first-method-encrypted data content key can be derived from the second method encrypted data content key using a second cryptographic method media key. The data content key or the first-cryptographic-method-encrypted data content key is encrypted using a second cryptographic method, which is different from the first cryptographic method, to obtain a second-method-encrypted data content key and the second-method-encrypted data content key is stored on the medium. A method of reading data from a storage medium checks, whether the storage medium is recorded using a first recording method or using a second recording method. If the storage medium is recorded using the first recording method, the data content key is recovered using the second encryption method media key, and the encrypted data content is decrypted using the first encryption method and the recovered data content key. The present invention creates an upgrade path for a compromised copy protection technology.</p> |
