A trusted system having at least one repository for controlling use of digital works in accordance with usage rights associated with the digital works. The system comprises means for receiving a request to access a digital work in accordance with usage rights associated with the digital work, the usage rights specifying a manner of access and indicating a security class, means for determining a security level of a repository controlling the requested access, and means for granting the request and permitting exercise of the manner of access specified in the usage rights associated with the digital work in accordance with the usage rights if the security level of the repository corresponds to the security class specified in the usage rights associated with the digital work. The security class indicates a security level of a repository that can access the digital work, and the usage rights are expressed with a grammar. In addition, an authorization object is used for identification of the repository, the physical integrity of the repository is secured, and digital works are accessed only through a transmission transaction protocol.