What Is the “Difficulty Bomb” in Some PoW-to-PoS Transition Plans?

The "difficulty bomb" is a mechanism coded into the protocol of some PoW blockchains, notably Ethereum, to intentionally and exponentially increase the mining difficulty over time. The purpose is to make mining progressively harder and eventually unprofitable, thereby forcing miners to transition to the new Proof-of-Stake system.

It acts as a countdown timer to a network-wide transition, preventing a permanent fork of the old PoW chain. This mechanism ensures a unified shift to the new consensus model.