How Does the ‘Halving’ Event in PoW Networks Affect the Security Budget?

Halving is the periodic reduction of the block reward for miners. Since the block reward is a major component of the network's security budget (the incentive to mine), a halving event reduces this budget.

This could theoretically lower the hash rate if transaction fees don't rise to compensate, potentially making the network slightly less secure or more susceptible to a 51% attack if the price doesn't increase.