How Can a Blockchain Network Defend against a 51% Attack?
A blockchain network can defend against a 51% attack through several mechanisms. One is to increase the network's hash rate, making it more expensive for an attacker to gain control.
Another is to implement a "modified proof-of-work" algorithm that is resistant to specialized mining hardware. Some networks may also have built-in checkpoints or emergency protocols that can be activated in the event of an attack.
Finally, the community can coordinate a hard fork to a new chain, effectively invalidating the attacker's chain.
Glossar
51% Attack
Dominance ⎊ The 51% attack, within cryptocurrency contexts, represents a scenario where a single entity or coalition controls more than half of a blockchain network's hashing power or stake.
Mining Pools
Structure ⎊ These collaborative entities aggregate the hash power contributions of numerous individual miners to smooth out the probabilistic variance in block rewards.
Hard Fork
Disruption ⎊ A hard fork represents a radical divergence in a blockchain’s protocol, creating a permanent split and typically resulting in a new cryptocurrency.
Emergency Protocols
Mitigation ⎊ Emergency protocols within cryptocurrency, options trading, and financial derivatives primarily focus on curtailing systemic risk stemming from volatility cascades and counterparty exposure.