METHOD FOR BINDING DIGITAL LICENSE TO PORTABLE DEVICE AND FOR CHECKING OUT OR CHECKING IN DIGITAL LICENSE FROM OR TO PORTABLE DEVICE IN DIGITIZED RIGHT MANAGEMENT (DRM) SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide an enforcing method for enhancing digital license right in order to prevent illegal conducts. SOLUTION: In order to render a digital contents encrypted according to a contents key (KD) on a first device having a public key (PU1) and a corresponding private key (PR1), a digital license corresponding to the contents is acquired. The digital license houses the contents key (KD) in an encrypted form. The encrypted contents key (KD) from the digital license is decrypted to get the contents key (KD), and the public key (PU1) of the first device is acquired from the first device. Then, the contents key (KD) is encrypted to be (PU1 KD)) according to the public key (PU1) of the first device, a sub license corresponding to and based on the acquired license is configured, where the sub license contains (PU1 KD)). Thereafter, the configured sub license is forwarded to the first device.