## 1 Introduction
For example, the multicast forwarding tree set up by PIM-SM and IGMP/MLD, only knows the multicast states (whether or not the subnet has multicast members), but it lacks of the effective control over multicast members (who joins/leave the multicast group). Figure 1: The UIN basic network architecture. This operation mode may results in serious security threats such as Denial of service (DoS), eavesdropping and masquerading [28]. In brief, IP multicast has the following problems [19; 29; 30]:  
* IP multicast lacks of an effective multicast source and receiver access control mechanism, and it has no limitations on multicast source and multicast receiver, which makes the deployment of Authentication Authorization Accounting (AAA) service more difficult. * The membership management in IP multicast is coarse-grained, which takes the router as the basic unit and cannot manage the concrete multicast members. * The join and leave operation may result in frequently multicast forward tree reconstruction, which have a great impact on the stabilization of multicast services. * The multicast data lacks of the security mechanism which may result in data leakage. * IP multicast routing protocol does not record the topology (In resource-constraint environments, maintaining topologies is costly and may not be feasible), and computes the multicast delivery tree in a distributed way, which is difficult to support QoS multicast. Lots of research efforts aim to improve and enhance multicast controllable, security, and mobility support. However, most of them introduce new complexity, which cannot fundamentally solve these problems. Considering that UIN can provide better mobility and security support, our previous work proposed a new Multicast service model for Identifier/Locator Separation (MILS) mechanism [19] which separates the multicast service identifier and multicast delivery structure to support scalable multicast by different mapping policies. Especially, the MILS introduces the Multicast Controller (MC) to perform the multicast source and receiver authentication, and sets up mapping between access network and core network for multicast to separate the multicast membership management and multicast data delivery. MILS can enhance the multicast security and support multicast mobility. However, it lacks of the detailed operations in term of multicast routing construction. While in this paper, we study the multicast problem based on UIN architecture, and aims to provide controllable and secure multicast scheme. More specifically, we design a Central-Controllable and Secure Multicast (CCSM) based on UIN. We introduce a Multicast Management Center (MMC) as the central controller for multicast service, and multiple MMCs are deployed in order to handle high availability and high concurrency. MMC is responsible for managing the group members and calculates multicast delivery tree. To distribute multicast routing entries, we first calculate the SPTs (Shortest Path Trees) and then send routing information to the relevant routers. The size of core network is the main factor that influences calculation performance. Luckily, the core network is designed to be much smaller than the whole network, so the calculation time is greatly reduced and intensive calculation is feasible. The contributions of this work can be summarized as follows:  
1. We propose a central-controllable and secure multicast based on UIN to provide the centralized multicast membership management and centralized multicast routing mechanism. 2. We design the operation flow of CCSM which includes multicast membership registration, join/leave, multicast tree construction and update, which is a new design different from the current IGMP/MLD and multicast routing protocols. 3. We analyse the mobility, security of CCSM, and evaluate its performance in terms of multicast delivery reconstruction cost and multicast join delay. 4. CCSM adopts the Publish/Subscribe model to provide multicast service which is suitable for IoT applications that deliver the messages among sensors.