Foundations of Blockchain

Implications of the attack

When a node controls the majority of the computation power of a network, it has a better chance of creating the new blocks than the rest of the network. When an attacker gets hold of the majority of the computation power, the attacker has some control over the ordering, inclusion, and exclusion of transactions. This doesn't mean the attacker can pollute the blockchain with invalid transactions. Since all the nodes in the network verify the transactions included in the blockchain, invalid transactions would be detected by the other networking nodes and the blocks would be discarded. An attacker would be able to cause the following complications in the blockchain:

• Delay some or all of the valid transactions from ...