What is Proof of Work (PoW) in blockchain technology?

Cryptos have become mainstream among much of the new generation in modern India. Almost everyone with an internet connection knows what they are and how they are put to use. However, even some common crypto terms like Proof of Work (PoW) can leave lay readers stumped. This is our attempt to remedy that.

What is Proof of Work (PoW)?

Proof of Work (PoW) is perhaps the most widely used mechanism to verify transactions on a blockchain and add new blocks to the chain. It is essentially a type of algorithm that does all of this by setting the rules for the work of mining. PoW thus plays a fundamental role in how blockchains work.

Under the PoW system, participants on a network must compete to earn the right to verify a block of transactions and add it to the blockchain. In the process, they create and earn new crypto tokens. The computational effort is required to do this “work” of mining new coins into existence. Hence the name “Proof of Work.”

The algorithm also adjusts the difficulty of this work to limit the rate at which new blocks can be generated by the network. And thanks to its design, PoW protects the integrity of the blockchain and prevents attacks by bad actors.

Understanding blockchain consensus mechanisms

Proof of Work is a type of consensus mechanism. Simply put, the consensus mechanism is a type of algorithm. It makes it possible for various actors on the network to agree on things and work together. Cryptos use consensus mechanisms to validate the authenticity of transactions and maintain the security of the underlying blockchain. Proof of Work is the first consensus mechanism, but there are many other options.

Some other consensus mechanisms are proof of stake, proof of authority, delegated proof of stake, and proof of history. Each type of consensus mechanism comes with its own unique benefits and drawbacks.

The consensus mechanism is extremely important because it influences the entire network mode of operation. Further, it determines how all its peers will make decisions to keep the ecosystem running. PoW is thus a key factor in the project’s future success or failure.

How the Proof-of-Work model works: Mining and more

To understand how Proof of Work functions, we need to understand mining. Mining is the process where new coins are brought into existence while users verify transactions on a blockchain. How PoW is implemented varies with each project. With Bitcoin, the PoW mechanism involves solving complex puzzles. It takes a lot of computing power to solve these puzzles. When a miner succeeds in solving the puzzle, they are given a chance to add new blocks to the chain. BTC rewards are put on offer as an incentive for miners.

So what’s this puzzle like? Puzzles, as you know, are of various types—word games, jigsaws… A term that will help us understand the PoW puzzle is “hash.” A hash is a mathematical function that encrypts data into the output of some fixed length—usually a number. Each block of transactions is associated with a specific hash in Proof-of-Work cryptos. To confirm a block, the miner must generate a target hash that’s less than or equal to the block. Because this isn’t easy, miners need to use devices with high computational power. The first miner with the target hash receives a reward.

So, miners are basically competing with other miners to find the hash. As miners compete, they contribute their computational power toward the security of the network. The more miners, the harder it is to manipulate transaction records. Hashes, therefore, make data more easily storable and the blockchain harder to hack. And PoW… Well, it is the algorithm that makes all of this possible. It institutes the system and runs it.

Bitcoin and other cryptos that use Proof of Work

There are so many cryptos out there that use the PoW consensus mechanism. According to data from April 2022 by data provider CoinCodex, approximately 64% of cryptos in the crypto market were using Proof of Work. That’s unsurprising because Bitcoin, which is by far the most influential model for cryptos, runs on PoW. Some of the most popular cryptos that use PoW, apart from Bitcoin, are:

• Dogecoin
• Bitcoin Cash
• Litecoin
• Monero

Up until as recently as September 2022, Ethereum, the world’s second-largest crypto by market cap, also used Proof of Work. However, the much anticipated and talked about Ethereum Merge changed that.

Challenges with Proof of Work

Proof of Work is no doubt a popular choice. While PoW is a well-established way to secure blockchain networks, several challenges are associated with it.

• Energy consumption: PoW is computationally intensive and requires a lot of energy. This has led to concerns about the environmental impact of PoW-based blockchain networks. For example, according to the Cambridge Bitcoin energy consumption index, Bitcoin uses 104.29 terawatt-hours (TWh) of electricity annually. That’s more than Norway’s yearly electricity consumption.
• Centralization: Because of the high costs of mining equipment and electricity, mining has become increasingly centralized. With lucrative returns coming to be associated with mining, large mining pools have begun to control a significant portion of the network’s hash power. This goes against the decentralized ethos of cryptos.
• Scalability: PoW can be slow and are not scalable enough for certain use cases. This is because the process of solving complex mathematical problems in mining can take a lot of time.
• Security: PoW-based networks work on the assumption that it is very difficult to solve the mathematical problems used to secure the network. The idea may not hold any water as breakthroughs in computer hardware or algorithms occur.
• Latency: Latency refers to the time it takes for a new block to be added to a blockchain network using the PoW consensus mechanism. One block is mined every 10 minutes on average in Bitcoin. That means it takes confirming a transaction takes time. High latency can lead to slower transaction processing and confirmation times.

Due to these challenges, alternative consensus mechanisms are being researched and developed as potential solutions. PoS is one of the strongest contenders to have emerged so far.

Differences between Proof of Work and Proof of Stake

Proof of Work (PoW) and Proof of Stake (PoS) are the two most popular consensus mechanisms in use today. In a decentralized network, they are used to validate transactions and achieve consensus on the state of the blockchain. The aim of both PoW and PoS mechanisms is to validate transactions in a decentralized way, but they work in different ways.

In PoW, as described earlier, network participants compete to solve a computational puzzle to earn the chase to verify transactions and receive the block reward. The puzzle’s difficulty is adjusted so that a new block is periodically added to the blockchain.

In contrast, with a PoS-based network, instead of using computational work to validate transactions and create new blocks, validators are chosen on the basis of their stake—that is, the amount of crypto they hold on the network. The idea is that the more invested a validator is, the greater incentive they have to act honestly and maintain the integrity of the network.

PoW is more secure, but it consumes a lot of energy. PoS, on the other hand, is more energy efficient and scalable. Another important difference is that PoW is less susceptible to centralization. Anyone can participate in mining, regardless of how much money they have. PoS can be more centralized, as it is harder for small token holders to participate in validating blocks.

Will PoS wipe out PoW?

Proof of Work and Proof of Stake are two important mechanisms in use in the world of crypto. Sure, PoS may be the newer and better mechanism, but it is unlikely that it will completely replace PoW in the near future. While PoS uses less energy and can be more cost-effective, it is not yet as widely adopted as PoW. The fact that the most popular crypto, Bitcoin, continues to use PoW and is considered very secure does not help either. So while PoS may be more widely adopted in the future, the possibility seems a bit distant.

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