What Is the Risk of a ‘Difficulty Bomb’ in Certain PoW Systems?

A difficulty bomb is a piece of code intentionally added to a PoW blockchain that progressively and exponentially increases the mining difficulty over time. It is designed to make mining so hard that it forces the network to transition to a new consensus mechanism, typically Proof-of-Stake, or implement a scheduled hard fork.

If the transition is delayed, the chain effectively stalls.