Proof of Work in Mining — Part 2
In the last article, we focused on the general features of the Proof of Work and on the way it functions in space. The second part of the series deals with its other features, equally vital for the efficient operation of the entire ecosystem.
Hash Rate
Hash rate is the number of hash calculations that the given mining equipment can perform. Every piece of equipment has a different hash rate. From GPUs to ASIC systems — application-specific integrated circuits — miners strive to have the most efficient equipment at their disposal in order to achieve the best possible hash rate, which increases the probability of mining a block in the blockchain and winning the reward.
Difficulty
Difficulty means how hard it is to find the hash required for mining a new block in a Proof-of-Work blockchain. The difficulty represents the number of possibilities/combinations for miners to guess the hash. The higher the difficulty, the more work miners have to do to guess the hash and append a new block. The difficulty is adapted in the Bitcoin blockchain so that new blocks are created every 10 minutes. If more miners join the Bitcoin network, thus contributing to an increase in the hash rate, the difficulty will go up and adapt so that the miners find the hash every 10 minutes on average.
The mining difficulty is adapted every 2016 block, that is every two weeks given that the average block needs 10 minutes to be dug. The Bitcoin algorithm guarantees such regulation very easily. If finding the previous 2016 blocks has taken more or less two weeks, then the difficulty will increase or decrease proportionately to the difference in time of two weeks.
Operating Principle of Mining Bitcoin with Proof of Work
Mining Bitcoins is more difficult than mining gold. Imagine that you have to repeat hashes trillions of times until you find the right one! Different blockchains can have different mechanisms, but let’s look at the baseline chain: Bitcoin. When mining coins in that platform, miners have to devise a block hash that meets specific criteria. To do so, they have to change some data in the block, and they have to do it A LOT. The process resembles a lottery.
Miners have to calculate 13.44 quadrillion hashes to generate one Bitcoin (as at January 2021). If we multiply this by 6.25, mining one block takes 84 quadrillion hashes! Miners have to repeat the calculations presented in the image above literally quadrillion times before a block is mined. This is exactly why digging Bitcoin consumes so much electric energy. On the other hand, it gives us the most secure blockchain in history.
Let’s imagine, purely hypothetically, that you’re trying to find that Bitcoin block and that everything you have is the best CPU on the market: AMD Ryzen 9 3900X, 12 cores. Mining one Bitcoin block at the current difficulty level would take you 225,730 years.
Unfortunately, digging Bitcoin on an ordinary computer is outright pointless. It was possible back in 2009 and 2010, when the hashing power in the network was still very low, but now — only highly efficient equipment, such as specialized ASIC diggers, can do the job. In those times, few people were interested in mining Bitcoin and the BTC price was several cents.
But why is Bitcoin mining so hard? And how does the mining process occur?
As we’ve seen before, the difficulty of the Proof of Work increases when more hashing power is added to the network. The difficulty and bit field of the block represents the number of zeros that the hash must-have. The number of zeros at the start of the hash is the condition to be met by miners. To generate a hash that meets that requirement, miners will have to follow the process set out below, trying different nonces until they create the required hash.
To create a block hash (or, in other words, to mine a block), specific conditions have to be met. Slight variance might occur depending on the applied algorithm, but the condition usually boils down to finding the hash, the value of which is barred by certain requirements. In other words, the hash has to start with a certain number of zeros.
The process is quite simple, yet highly repetitive (miners do it again and again, a billion or trillions of times).
When a miner finds the proper hash, they send it to the network and the remaining miners can easily verify whether the provided nonce generates the appropriate hash. The miner who has mined the block will also include a Coinbase transaction in it. This transaction corresponds to the reward they will get.
When mining Bitcoin, miners try to find hash values lower than the target value (this is the field in every blockchain block). The hash value must be lower than the value represented by the bit field in the block header. This also means that the target hash will have to start from a certain number of zeros. This number of zeros will increase as the difficulty increases. The higher the difficulty, the harder it is to find a block, as it is harder to find a hash meeting the required goal.
Why do those “zeros” in the hash affect the difficulty so much? Do you think that the likelihood of block hashing with, say, 20 simple zeros is very low? It’s like trying to find the winning ticket in a jumble of trillion lottery tickets which start from 20 zeros. Or rolling dice and acquiring the same number of dots 15 times in a row. This is a very, very low probability, and this is why it’s so difficult.
Currently, Ethereum is based on POW, which makes this network (and even more so the groundbreaking metaverse project Etheros) one of the most secure and longest developed outside of Bitcoin. Perhaps in time, Ethereum will move to a POS (proof of stake) protocol. Regardless of when this happens, we are sure it will bring additional benefits not only to the network itself but also to the users who use Etheros on a daily basis.
Etheros Links
Twitter — https://twitter.com/EtherosIo
Telegram Community — https://t.me/Etherosio
Medium — https://medium.com/etheros
Reddit — https://www.reddit.com/r/Etheros
Telegram Official — https://t.me/EtherosioOfficial
Linkedin — https://www.linkedin.com/company/etherosio
Instagram — https://www.instagram.com/etheros.io/
Facebook — https://www.facebook.com/etherosio
