Proof of Work (PoW - Proof of Work) is basically a protocol for the prevention of attacks aimed at disrupting the functioning of a system and unwanted messages sent by e-mail called Spam. The Proof of Work protocol originated in a 1993 paper by computer experts Cynthia Dwork and Moni Naor. By 1999, it was included in the literature with the efforts of researchers named Markus Jakobsson and Ari Juels.