What Security Measures Can Smaller PoW Coins Implement to Mitigate the Risk of a 51% Attack?

Smaller PoW coins can implement several security measures. One common approach is using a multi-algorithm mining system, which diversifies the required hardware and makes it harder for a single entity to amass 51% of the total power.

Another measure is implementing a delayed or checkpoint-based finality mechanism, making transaction reversal more costly or impossible. Some coins also utilize "Auxiliary Proof-of-Work" (AuxPoW), where a coin is mined simultaneously with a larger, more secure coin.

Community vigilance and rapid protocol adjustments are also crucial.