Proof of Work (PoW)
Proof of work (PoW) is a form of cryptographic proof in which one party (the prover) proves to others (the verifiers) that a certain amount of a specific computational effort has been expended.
PoW was first proposed in 1993 by Moni Naor and Cynthia Dwork as a way to prevent denial-of-service attacks and other service abuses such as spam on a network. In their 1993 paper, "Pricing via Processing or Combatting Junk Mail," they argued that requiring users to perform a small amount of work before sending a message or accessing a resource would make it more difficult for spammers and attackers to abuse the system.
It was later adopted by Bitcoin in 2009 as a way to secure its blockchain and prevent double-spending.
Proof-of-work schemes are asymmetric, meaning that the work required to generate a proof is difficult for the prover but easy for the verifier to check. This is also known as a CPU cost function, client puzzle, computational puzzle, or CPU pricing function. Another common feature of proof-of-work schemes is built-in incentive structures that reward participants for allocating their computational resources to the network. In the context of cryptocurrencies, this reward typically comes in the form of cryptocurrency tokens.
Proof-of-work algorithms are not meant to prove that work was done or that a puzzle was solved. Instead, they are meant to make it difficult to manipulate data by requiring a lot of energy and hardware to do so. In other words, proof-of-work algorithms make it very expensive to cheat on the system.
PoW in blockchain
Last updated