An information reproducing method and an information reproducing device in which the key renewal block (KRB) of the latest version is selectively used to encrypt the content to store the encrypted contents in a recording medium. A plural number of KRBs of different generations and versions are stored in a recording medium. If the latest KRB is detected, it is stored in a memory unit within the recording and/or reproducing device. A plural number of KRBs having plural different generations or versions are stored on the recording medium. With the present method and device, in storing the content in the recording medium, the latest usable one of the KRB in the memory unit of the reproducing device and plural KRBs on the recording medium is detected to acquire an encrypting key, such as a media key, to execute the content encryption. In this manner, the encrypted content based on a KRB of a newer version can at all times be stored on the recording medium.