Traditional identification-centric RFID system (IRS) is designed to provide services of object identification/tracing/locating, but it has some shortcomings when encountering a dynamic environment in which the status of the systems and the service requirements of users/objects may change continuously. Very recently a new Code-centric RFID system (CRS), which is far different from the traditional IRS, is proposed to provide on-demand fashion code re-writing and to suit for more flexible user-centric applications. However, at the current stage the there is no secure and efficient scheme to manage the mobile code updating and authentication process in CRS. In this paper, a new scheme is proposed to provide efficient and dynamic mobile agent code updating management. In addition, to prevent the CRS system form possible attacks from malicious users, an IDPKC-based digital signature generation and authentication protocol is proposed.