Abstract: A method for managing a specific domain (or user domain), for example leaving the domain by a specific device after fully returning a Rights Object (RO) taken by the specific device, instead of deactivating the RO, when leaving the specific domain, the method in which the device desiring to leave the specific domain moves its RO to another device desiring to join the specific domain and thereafter leaves the specific domain under the control of a Domain Authority/Domain Enforcement Agent (DA/DEA).

Abstract: A system for protecting contents comprises a first device for storing and reproducing contents purchased by a user; a server for issuing usage rights of contents; and a second device for reproducing contents protection mechanism-applied contents, and if contents to be copied from the first device are not protected by the protection mechanism, obtaining the usage rights from the server and converting the unprotected contents into contents under protection of the protection mechanism. When contents purchased by the user is not protected by the DRM, the DRM-employed reproducing device can obtain usage rights with respect to the corresponding contents from the rights issuer. And then, the purchased contents are converted into the contents that can be protected by the DRM.