# Blockchain-Assisted Adaptive Reconfiguration Method for Trusted UAV Network
## 4 Recommended Scheme
### Trusted Network Reconfiguration
#### 4.3.3 Blockchain Update and Synchronization  
The two-stage consensus data consensus of this scheme produces a deterministic consensus result, a common subset of local state transactions ACS, at the delegated agent nodes eventually through the decentralized stable transmission of DRBCs and external provable smart contracts. at this point, each correct delegated agent node is able to unify the algorithm for decision consensus, generate new configuration information and create new blocks. The delegated agent nodes update the local blockchain while multicasting new blocks according to the trusted nodes on the current blockchain. The node that receives the new block compares the height of the local blockchain, and if the difference in height with the new block is greater than 1, the node requests synchronization of the blockchain from the delegated agent node that sent the block; otherwise, it verifies the new block and updates the local blockchain.  
After the data consensus is completed, the upper layer network delegates the agent node to calculate the global state data of the nodes and process the global trust discount table and neighbor list table by statistics and clustering to update the trust degree of the network nodes, determine the regional central node, and reconfigure the trusted drone network in the current state. The drone network blockchain adaptively configures the trusted network periodically by continuously adding new blocks. The authorized nodes that make up the upper virtual network run a two-stage consensus process. The adaptivity is reflected in the network system cycle consensus, where any participating node directly requests the upper layer network to initiate consensus if it senses excessive changes in the physical structure or low local trustworthiness of neighboring nodes during the cycle. The process of reconfiguration of the trusted network is the continuous consensus process of the blockchain. The consensus flow is shown in Figure 3.  
The delay of new blockchain block increase depends on the time of data consensus to reach an agreement, although the drone network will be frequent network partitioning, an asynchronous consensus algorithm can eventually reach a deterministic consensus. However, the original intention of this scheme design is to maintain the overall trustworthiness of the network by dynamically reconfiguring the network, so in order to meet the needs of practical applications, but the asynchronous consensus timeout, the consensus algorithm of multi-point proof of authorization (DPOA) is automatically started. DPOA is similar to the proof-of-authority consensus algorithm because the nodes participating in consensus in each cycle are the elected best state nodes, so after the asynchronous consensus timeout, the data consensus can be completed as long as there are more than 2 nodes reaching consensus, and the local transaction data set of the node with the smallest agent node ID among them is the final data consensus result. To ensure that the reconfiguration of the UAV network is completed within the specified safe time.  
Figure 3: Two-stage consensus process in an authorized node \(ID^{i}_{A}\).