By Alexander Lawn
Bitcoin mining is the process by which the transaction information distributed within the Bitcoin network is validated and stored on the blockchain. It is a term used to describe the processing and confirmation of payments on the Bitcoin network.
What makes the validation process for Bitcoin different from traditional electronic payment networks is that there is no need for an issuing bank, an acquiring bank, merchant accounts or mandatory centralized clearing houses, such as Visa and MasterCard, holding onto funds until they process transactions at the end of each day.
Bitcoin mining is a process that anyone can participate in by running a computer program. In addition to running on traditional computers, some companies have designed specialized Bitcoin mining hardware that can process transactions and build blocks much more quickly and efficiently than regular computers. The process of validating transactions and committing them to the blockchain involves solving a series of specialized math problems.
Each Bitcoin miner is competing with all the other miners on the network to be the first one to correctly assemble the outstanding transactions into a block by solving those specialized math problems. In exchange for validating the transactions and solving these problems, Bitcoin miners are rewarded for all of the transactions they process. They receive fees attached to all of the transactions that they successfully validate and include in a block. In addition to transaction fees, miners also receive an additional award for each block they mine.
This block reward is also the process by which new bitcoins are created, as specified by the Bitcoin protocol. Currently, that reward is 12.5 new bitcoins (worth over $7,000 at time of publication) for each block mined. That reward decreased from 25 bitcoins on June 9, 2016.
Because the reward for mining blocks is so high, the competition to win that reward is also high. At any moment, hundreds of thousands of supercomputers all around the world are competing to mine the next block and win that reward. In fact, the total power of all the computers mining Bitcoin is over 1000 times more powerful than the world’s top 500 supercomputers combined. And the competition doesn’t stop—the Bitcoin network has gotten stronger and stronger over the past several years, growing by as much as 10 percent per month. The strength of the Bitcoin network is very important for security because in order to attack the network, an attacker would need to have over half of the total computational power of the network. The more miners that are mining Bitcoin, the more difficult and expensive it becomes to perform this attack.
In order to have an edge in this global competition, the hardware used for Bitcoin mining has undergone various iterations, starting with using the humble brain of your computer, the CPU. The CPU can perform many different types of calculations including Bitcoin mining, but is designed to be general purpose. Early miners soon discovered that the calculations could be run faster and more efficiently using a graphics card (GPU), which is the computer chip that handles complex 3D imaging algorithms. Aside from being able to process Bitcoin's transactions faster and more efficiently, the graphics card setup in many desktop PCs meant more than one graphics card could be used per computer. This was already a feature of high-end gaming and 3D design computers. As such, Bitcoin’s popularity grew among those associated within such fraternities, as they could dedicate their machines to mine bitcoins, and thus cover the cost of their hardware.
But this still wasn’t the most power-efficient option, as both CPUs and GPUs were very efficient at completing many tasks simultaneously, and consumed significant power to do so, whereas Bitcoin in essence just needed a processor that performed its cryptographic hash function ultra-efficiently.
Enter the Field Programmable Gate Array (FPGA), which was capable of doing just that with vastly less demand for power. There was one issue: due to the reprogrammable nature of the chip, it had a significantly high cost for a chip that solved blocks at the same rate as a GPU. Its real virtue was the fact that the reduced power consumption meant many more of the chips, once turned into mining devices, could be used alongside each other on a standard household power circuit.
As Bitcoin’s adoption and value grew, the justification to produce more powerful, power-efficient and economical per-chip devices warranted the significant engineering investments in order to develop the final and current iteration of Bitcoin mining semiconductors: the Application Specific Integrated Circuit, or ASIC. ASICs are super-efficient chips whose hashing power is multiple orders of magnitude greater than the GPUs and FPGAs that came before them. Succinctly, it’s a custom Bitcoin engine capable of securing the network far more effectively than before.
The year 2013 was very much a land grab for Bitcoin ASIC technology as the first ASICs became available and many different companies raced to create the most power chips using cutting edge semiconductor manufacturing processes. In the years since, several Bitcoin mining chip manufacturers have focused on optimizing for efficiency, rather than total power, since mining is a very energy-intensive process.
Because of the high energy costs for running a powerful Bitcoin miner, many operators have elected to build data centers known as mining farms in locations with cheap electricity, such as near a hydroelectric dam in Washington State or even in foreign countries like Iceland and Venezuela.
Another advancement in mining technology was the creation of the mining pool, which is a way for individual miners to work together to solve blocks even faster. As a result of mining in a pool with others, the group solves many more blocks than each miner would on his own. However, the miners must split the rewards with the entire group. Today, the majority of mining on the Bitcoin network is done by large pools, several of which are based in China.
So far, Bitcoin mining has continued to grow stronger and more secure, even as the mining reward decreased at the 2016 halving.
Hailing from London, Alex Lawn is a well-known character on the cryptocurrency scene. He is responsible for not only the fundraising and building of some of the most successful branding in Bitcoin, specifically in hardware, but for bringing journalists working in the world’s financial and tech press up to speed on the subject of cryptocurrencies. Lawn works within disruptive finance alongside the principals of Bourne Capital.