What is the consensus algorithm used by Dogecoin?

Dogecoin initially used a proof-of-work (PoW) consensus algorithm, similar to Bitcoin and many other cryptocurrencies. However, in 2014, Dogecoin implemented an auxiliary proof-of-work (AuxPoW) algorithm to enhance its security.

AuxPoW allows Dogecoin to be merge-mined with Litecoin, another cryptocurrency that uses the Scrypt PoW algorithm. Merge mining means that miners can simultaneously mine both Dogecoin and Litecoin, effectively securing both blockchains with the same computational resources.

This implementation significantly increased Dogecoin's security by leveraging the larger hash rate of Litecoin's network. It also helped prevent 51% attacks and increased the overall robustness of the Dogecoin blockchain.

So, while Dogecoin originally used a traditional PoW algorithm, it now utilizes the AuxPoW algorithm to enhance its security and reliability.