## 4 Proposed Work  
This section introduces an advanced hybrid architecture that integrates Radial Basis Function (RBF) networks with blockchain technology to improve security, facilitate efficient key distribution, and allow proactive threat detection in Zigbee-enabled IoT networks [19]. The proposed approach utilizes the trust-based blockchain system (pBCS) to securely distribute keys across Zigbee-enabled IoT devices. Blockchain: The \"Trust Security Service Provider (B-TSSP)\" is the proposed BCS. All Zigbee-enabled IoT devices are safe because the same cryptographic credentials are used on the Zigbee edge device with trusted storage across the Zigbee IP protocol stack. This capability is achieved through a physically unclonable function (PUF) mechanism, as illustrated in Figure 2. The trusted blockchain will create the signed certificates using a private validator key commonly used as a root of trust. Before performing any operations, all Zigbee coordinators, routers, and end devices must enroll with a BCS. The Zigbee IP Coordinator is the full-function device that can initiate a new Zigbee network and maintain the blockchain system. As per Zigbee alliance specifications, there must be a single coordinator for each Zigbee network. The end user will communicate with any ZED only through the Zigbee IP Coordinator when an existing Zigbee network needs to accommodate the addition of a new end device. Then, the user must change the network's status through Blockchain DApps from a closed to open state and send the exact request (open state) command to the coordinator. Then, the smart contract of the blockchain system will verify the state and change the system's state. When the Zigbee network switches to an open state, the coordinator authorizes the broadcast of a join response message, telling all ZD that the network is now accepting new joining requests and is in an open state. On the other hand, the Zigbee network cannot take any new devices once it has reached a closed state. Only the Trusted Permissioned Blockchain can create authentically signed certificates [20,21]. Any router or Edge device that holds the validator's public key can validate the signed certificate and guarantee the public key's integrity. Lastly, the Secure Communication Protocol transfers data between the ZED and the coordinator through a registered ZR. This secure communication protocol derives the shared secret key between the coordinator and edge devices in the untrusted field, authenticated and encrypted communication. In this secure communication protocol, we performed mutual authentication with less non-volatile memory (ROM). Before performing the mutual authentication, the BCS must enroll the blockchain validator and ZED. This proposed BCS solves the problem of less usage of non-volatile memory and improves key management. The blockchain validator will access the shared ledger that stores the digital key credentials of all the enrolled ZED and Zigbee Routers (ZR), including the Zigbee Coordinators. The proposed Zigbee IP protocol stack security architecture, is made up of \"Zigbee IP alliance security\" and \"applications security\". The link layer (MAC) and PHY (802.15.4) security are supported by the IEEE 802.15.4 standard. The Zigbee IP alliance offers network adaptation layer security, network layer security, routing layer security, transport layer security, application support sublayer security, application layer security, and blockchain service providers. Blockchain--The Trust Security Service Provider: The proposed blockchain system, called Blockchain: The Trust Security Service Provider (B-TSSP), provides an open trust model that allows end-to-end security among IoT-enabled Zigbee devices by reusing the same cryptographic credentials among the Zigbee IP protocol stack on the same Zigbee edge device. In other words, this proposed BCS provides the trust security service to the Zigbee IP protocol stack. By providing many security services, the B-TSSP makes the security procedures possible.