Bitcoin Diamond (BCD) is a permissionless, decentralized cryptocurrency that resulted from a November 2017 hard-fork of Bitcoin. Bitcoin Diamond differs from Bitcoin in several ways. Instead of using the SHA-256d Proof-of-Work consensus mechanism Bitcoin uses, Bitcoin Diamond uses the optimised X13 Proof-of-Work consensus mechanism, which is designed to target GPU mining and be ASIC-resistant. Bitcoin Diamond also implements a larger block size than Bitcoin, increases the block size from 1 megabyte to 8 megabytes, and can eventually be increased to 32 megabytes. Bitcoin Diamond has implemented replay protection for added security, the Lightning Network layer-2 payment protocol for faster transaction times, and SegWit technology which increases the max TX per day to around 4.8 million, about four times that of Bitcoin. The total supply of Bitcoin Diamond able to be mined is capped at 210 million, which is ten times larger than the total supply of Bitcoin.