Definition of Proof of Work

Proof of work is a system that requires a workable, but not a significant amount of effort, to prevent any kind of malicious use of computing power, like launching denial of service attacks or sending spam emails.

This method was eventually adapted to secure digital money in 2004, by Hal Finney with the idea of reusable proof of work, using the SHA-256 algorithm. Later in 2009, Bitcoin became the first adopted application of Hal Finney’s proof of work idea. Proof of work is the basis of many other cryptocurrencies, allowing decentralized, secure consensus.

PoW (Proof of Work) is a decentralized consensus mechanism that requires members of a network to solve an arbitrary mathematical puzzle in order to prevent anybody from cheating the system.

In Bitcoin and other cryptocurrencies, proof of work is a common way to verify transactions and create new units. Bitcoin and other cryptocurrency transactions may be carried out peer-to-peer securely without the need for a trusted third party due to proof of work.

Proof of work at scale requires a lot of power, which only grows as more miners join the network. Proof of Stake is one of several unusual consensus algorithms that were developed as a substitute for proof of work.

How does Proof of Work, work?

Bitcoin is a cryptocurrency that is based on a distributed ledger called a blockchain. The Bitcoin blockchain is a decentralized ledger that records all bitcoin transactions in chronological blocks, allowing no individual to spend any of their coins twice.

The ledger is public, or “dispersed,” to prevent tampering; a modified version would be quickly rejected by other users.

Hashes, long strings of numbers that function as proof of work in practice, are how users detect tampering. Only one hash will be generated if a certain collection of data is put through a hash function (bitcoin employs SHA-256).

If the data set is small, however, it will take more time to check every possible hash. Because of the “avalanche effect,” even a minor variation in any part of the original data would result in an unrecognizable hash. The length of each hash produced by a specific function is always the same.

The hash is a one-way process that can only be used to verify that the data that generated the hash matches the original data. The Bitcoin network adjusts the “difficulty” level in order to make generating any hash for a set of Bitcoin transactions seem difficult. 

A modern computer could just generate any hash for a set of Bitcoin transactions, so the process is made to appear like work by the Bitcoin network. The setting of this option is changed so that a new block is “mined”, created by generating a valid hash about every 10 minutes.

Setting difficulty is determined by setting a “target” for the hash: the lower the target, the smaller the set of valid hashes, and the more difficult it is to produce one. This implies that a hash that starts with a very long string of zeros in practice.

PoW mining

How can miners ensure that they generate a hash less than the target when there is only one possibility for each set of data? They modify the input by adding a nonce (“number used once”), which guarantees that no two hashes are alike. 

The block is added to the blockchain and the network is notified if a valid hash has been discovered. Mining is a competitive endeavor, but it’s more of a lottery than a competition. Every ten minutes, on average, someone will produce acceptable proof of work, though who that person will be is anyone’s guess.

Miners pool their resources to enhance their chances of discovering blocks, which results in transaction fees and, for a time, newly-created bitcoins. It’s impossible to change anything on the blockchain because doing so would result in re-mining all subsequent blocks.

This also makes it hard for a single user or group of users to dominate the network’s computing power, as the hardware and energy necessary to complete hash functions are costly.

How does Proof of Work validate transactions?

The work is meaningless. It consists of SHA-256 hashing iterations in the case of Bitcoin. The “winner” of a round of hashing combines and archives transactions from the pool into the next block, even though they are not necessarily linked.

Because the “winner” is randomly selected based on the amount of work accomplished, it encourages everyone on the network to act honestly and record only genuine transactions. Because they are decentralized and peer-to-peer by nature, blockchains like cryptocurrency networks require some means of achieving both consensus and security. 

One such approach is proof of work, which makes it impossible to attempt to take over the network due to its high energy requirements.

Other methods for proof are less costly in terms of resources but have disadvantages or flaws such as proof of stake (PoS) and proof of burn. The network and the data stored within it would be vulnerable to attack or theft if there is no verification method.

Nodes on a network must provide evidence that they have invested computational power (work) in order to produce consensus in a decentralized manner and prevent bad actors from taking control of the network using proof of work (PoW).

Why is Proof of Work important for cryptocurrencies?

Because they are decentralized and peer-to-peer by design, blockchains like cryptocurrency networks need some method of achieving both consensus and security.

The rigorous proof of work is one such approach that makes it impossible to breach the network. There are other proof techniques that are less resource-intensive but have drawbacks or faults, including proof of stake (PoS) and proof of burn.

A proof mechanism is required to maintain the network and data within it safe from attack or theft.

Proof of Work (PoW) is used by approximately 64% of the overall market capitalization of cryptocurrencies. The following are some of the most well-known cryptocurrencies: Bitcoin, Dogecoin, Bitcoin Cash, Litecoin, and Monero.

Proof of Work vs Proof of Stake

Although proof of work and proof of stake are two distinct types of consensus algorithms for Bitcoin, there are significant distinctions between them.

Both methods verify incoming transactions and add them to a blockchain. Rather than miners, network participants are known as validators in the proof of stake system. One key distinction is that rather than attempting to solve mathematical problems, validators store a specified amount of bitcoin, their stake, in a smart contract on the blockchain.

In exchange for “staking” cryptocurrency, they receive the opportunity to validate new transactions and earn a reward. However, if they incorrectly validate bad or fraudulent data, they may lose some or all of their stake as a penalty.

Proof of stake makes it easier for more people to get involved in blockchain networks as validators. Staking crypto isn’t necessary since there’s no requirement to buy pricey computing equipment and waste huge quantities of electricity. All you need are coins.

The more tokens are kept in a wallet, the more mining power it is assigned. PoS has several drawbacks, including the possibility of a 51% attack in smaller cryptocurrencies and financial incentives to hoard coins rather than utilize them.

PoW advantages and disadvantages

When it comes to looking at the advantages and disadvantages of proof of work, the list could be pretty long, but here are a few significant points.

The benefits of proof of work are that it provides a decentralized method of verifying transactions, it lets miners earn crypto rewards and it has a high level of security. However, the downside is that it consumes too much energy and power, it is inefficient with slow transaction speeds and it has expensive fees, and mining is often an expensive process.

But to summarize it all, the most popular of the two main consensus algorithms for validating transactions on blockchains is proof of work (PoW). 

Miners that use proof of work ensure that only genuine transactions are recorded on the blockchain, albeit with some limitations. Miners help secure the blockchain by verifying and authenticating transactions. In this way, they also assist. 

Miners secure the blockchain’s security by keeping track of who has access to which addresses, and they also assist protect those transacting blockchain-based enterprises from costly assaults.