PoW vs PoS is a common topic in the blockchain and cryptocurrency world. Both represent different consensus mechanisms that are used to run blockchain. In this article, we will explore the differences between the two mechanisms and their tradeoffs.
What is Proof of Work (PoW)?
Proof of Work (PoW) is the consensus algorithm adopted by Bitcoin and many other cryptocurrencies. Its main aim is to validate and verify transactions, without the need for third-party intermediaries.
On a PoW network, transactions are verified by miners. They are participants that use a great amount of resources to ensure the network continues to run securely and correctly. Among other tasks, miners create and validate blocks of transactions. To compete for the right to validate the next block, they require highly specialised mining hardware to solve complex mathematical puzzles.
The first miner that manages to find a valid solution for these mathematical puzzles, earns the right to add their block to the blockchain and obtain a block reward. Block rewards are made up of newly generated cryptocurrencies plus transaction fees. WhETHer miners can make profits depends on how much block reward they earn, as well as how much energy is spent to mine the block.
What is Proof of Stake (PoS)?
Proof of Stake (PoS) is a consensus algorithm that is an alternative to Proof of Work. It aims to overcome the scalability limitations of PoW networks. PoS is the second-most-popular algorithm adopted by well-known cryptocurrencies like Binance Coin (BNB), Solana (SOL), and Cardano (ADA).
Compared to PoW, PoS has a fundamentally different way of determining who verifies transactions. There are no miners on PoS blockchains. Rather than relying on powerful computers to compete for block validation rights, PoS validators rely on the amount of crypto they stake.
Staking is the process whereby participants need to lock a certain amount of coins in a specific smart contract on the blockchain to be eligible to validate a block. The PoS protocol will then assign a participant to validate the next block. Depending on the network, this selection can be done randomly or according to the amount that was staked. The selected validator can receive transaction fees as block rewards. Oftentimes, the more coins they lock up, the greater the probability of being selected.
PoW vs PoS
PoS was initially introduced to address the shortcomings of PoW. Indeed, PoS is more scalable and boasts higher transaction speed. In addition, PoS is more environmentally-friendly.
However, some supporters of PoW argue that PoW is harder and more expensive to attack because PoW networks are run on a lot of resources.
In some cases, many can contend that PoS gets rid of any centralization risks. Some miners accumulate their mining resources in mining pools for a greater chance to get the block rewards. They invest as much as millions of dollars and control thousands of ASIC mining hardware to generate as much hashing power as possible.
As of December 2021, the top 4 mining pools togETHer control around 50% of the total Bitcoin hashing power. This is a form of centralization in itself as individual miners would find it extremely difficult to mine their own blocks. PoS, on the other hand, replaces mining power with staking, hence increasing the chances of people without huge computing power to validate blocks.
PoW also presents some security risks. A 51% attack may occur, and this happens when a malicious actor or organisation is able to control over 50% of the total network hashing power. The attacker may override the blockchain consensus mechanism and commit fraudulent acts that will cause the blockchain to collapse potentially. If someone were to commit a 51% attack in a PoS blockchain, they would have to own over 50% of the coins, which is highly unlikely.
In Conclusion
We hope that this article has given you a clearer understanding of PoW vs PoS and their tradeoffs. Regardless of which consensus mechanism you support, both have their own benefits when chosen to run a blockchain.
