Does PoA Completely Solve the “Nothing at Stake” Problem, or Just Mitigate It?

Decred (DCR) is a prominent example of a cryptocurrency that uses a hybrid PoW/PoS consensus mechanism, which is a form of Proof-of-Activity. Decred's model mandates that both miners and stakers must approve all transactions and rule changes, giving both groups a check on the other's power.

This dual-approval system is central to its security and governance.