is 952.32 KB, has a resolution of 1535x1535 pixels and was uploaded on November 29, 2018 @ 11:29 am by user: hildecht. It is filed under the tags: blackcoin, peercoin, scrypt, proofofstake, proofofwork system. Click the blue button at the top to freely download: Coin Stack Peercoin Proof-of-stake Cryptocurrency Bitcoin Proof-of-work System png.