Blockchain Consistency Check Protocol for Improved Reliability

Blockchain is a technology that provides security features that can be used for more than just cryptocunencies. Blockchain achieves security by saving the information of one block in the next block. Changing the information of one block will require changes to all the next block in order for that change to take effect. Which makes it unfeasible for such an attack to happen. However, the structure of how blockchain works makes the last block always vulnerable for attacks, given that its information is not saved yet in any block. This allows malicious node to change the information of the last block and generate a new block and broadcast it to the network. Given that the nodes always follow the longer chain wins rule, the malicious node will win given that it has the longest chain in the network. This paper suggests a solution to this issue by making the nodes send consistency check messages before broadcasting a block. If the nodes manage to successfully verify that the node that generated a new block hasn't tampered with the blockchain than that block will be broadcasted. The results of the simulation show suggested protocol provided better security compared to the regular blockchain.