An alternative solution to avoid relying on proof of work (POW) mining is to use a replacement consensus mechanism known as POA, in which we trust a set of known validators (authorities) to accept transactions. In other words, POA validators are staking their identity and voluntarily disclosing who they are in exchange for the right to validate the blocks. Unlike POW, POA is a centralized mechanism that delivers comparatively fast transactions, thus POA deployment is used by private (enterprise) and some public testing networks (for example, the popular Kovan and Rinkeby test networks).

To set up a private chain with Geth and POA, you will need to reiterate the same Puppeth procedure that was presented earlier, except for choosing the consensus engine. Start Puppeth, follow the questionnaire, and choose POA as the consensus engine. In this case, you'll need to determine the validator accounts (accounts that are allowed to seal). For that, copy and paste the Ethereum accounts that were created earlier by Geth. Of course, you can define as many sealers as you like but POA is able to work with a single node and only one sealer:

Keep in mind that POA doesn't have mining rewards, and therefore it's highly recommended that you allocate enough ether (defined in the unit of wei) to your accounts first, and then initialize your nodes with the resultant POA genesis file.

Ta-da! No more mining.

After laying out the different available deployment environments, it's time to run our auction DApp.