The invention discloses improved encrypted/decrypted contents, and a method and apparatus for issuing encrypted contents. In one embodiment, a first device encrypts contents by using a dual hash chain technology. The first device maintains forward hash chains. A second device maintains reverse hash chains. A content key for encrypting contents is guided out through forward and reverse hash chain values. The second device dose not know seeds used for generating forward hash chains and thus a content key cannot be produced, therefore, encrypted contents are less liable to leak. Moreover, the invention provides a technology for re-encrypting contents through a proxy re-encryption (PRE) technology. In this way, encrypted contents can be provided to a request device for decryption with need of forward and reverse hash chains. Furthermore, the invention provides a technology, having a fine-grained access control function, for issuing encrypted contents to the request device.