What Is the Role of Transaction Fees in Network Security?

Transaction fees play a crucial role in network security, especially as the block reward subsidy decreases (e.g. after a halving). They incentivize miners or validators to include transactions in a block and prioritize transactions with higher fees.

Critically, fees ensure that the network remains secured by making it economically costly for malicious actors to flood the network with spam transactions or attempt a 51% attack. In the long term, fees are expected to become the primary source of network security funding.