An Improved Model of PBFT with Anonymity and Proxy Based on Linkable Ring Signature

At present, PBFT has become an important consensus mechanism in the blockchain due to its high efficiency. In PBFT, a primary node must be chosen. If the primary node is attacked, PBFT needs to select a new node as the primary node. The continuous occurence of such attacks makes PBFT become much less efficient. Considering the importance of the primary node, this paper proposes an improved model of PBFT with anonymity and proxy. The linkable ring signature technology is utilized to hide the primary node in the ordinary nodes, which can significantly reduce the risk of the primary node being attacked. This countermeasure improves the security of PBFT to some extent. Moreover, in this scheme, each node has its corresponding proxy node. When a node is not online for participating in the PBFT, its proxy node can be authorized to complete the whole steps in the consensus, which improves the reliability of PBFT.