Bitcoin Mining: The basics
Trying
to explain what Bitcoin is or how it works can be a complicated enough task as
it is, but at some point you have to delve into the minefield of – yes, mining.
Mention
the word mining and the uninitiated might conjure up an image of a man with a
pickaxe digging for precious metal. Although far from the reality, the analogy
of mining for gold can be a useful one when applied to the mining of bitcoin,
particularly as bitcoin has a finite supply and people are required to release
bitcoins into circulation by effectively ‘digging’ them out of a specially
encrypted code.
Take
those first groups of young men, all heading for the hills to find their
fortune in the gold rush and replace them with groups of Gen Y technophiles
gearing up their computers to solve complex algorithms for bitcoins and you
start to get the picture.
At
its most basic, bitcoin mining is a network of computers, crunching numbers to
solve mathematical problems. When they have found the answer, new bitcoins are minted.
If
you look into mining in more depth, you have to start talking about hash rates
and explaining the encryption algorithm, SHA256, which is used for many online
security systems (such as internet banking and email) but in this case has been
applied specifically to the security of the bitcoin network.
What
these computers are actually doing when they mine is unlocking blocks of
encrypted data to release bitcoins. These are released into a bitcoin address
and the successful miner gets the private key to access it.
This
provides a great incentive for people to mine and the more miners out there, the
more secure the bitcoin network becomes. This is because not only do miners
help issue the currency, they are also required to validate every bitcoin
transaction that takes place. These transactions are confirmed with every new
block mined.
However,
as the number of miners increases and competition grows, the chances of
successfully mining a block independently, goes down. This brings us on to the
genius behind the coding for the mining of bitcoin, which is in the elastic
difficulty of solving the equations, taking into account how many people are
mining at any one time. It was built in to help regulate the amount of currency
in circulation. So, as more people mine, the difficulty of the algorithm
increases to prevent the market being flooded with bitcoins.
There
is a predetermined rate of release for the currency, which means as more bitcoins
are mined, the chances of finding new ones diminishes exponentially. A block is
mined roughly every ten minutes. At the outset from 2009, one block released 50
BTC, but every four years, the amount halves, hence why the current worth of a
block is 25 BTC. This value will continue to halve until all 21 million
bitcoins have been mined into existence and this is expected to happen some
time around 2040.
The New Mining Boom
As
it becomes harder for people to successfully mine independently, bitcoin mining
pools have established to amalgamate computing power. When someone in the pool
mines a block, members of the pool get a share of the bitcoins, which are
allocated proportionately to the amount of work a miner has contributed.
To
take the gold analogy further, when there was plenty of gold available near the
surface, one man and his pickaxe could have done the job and got a good return
for his efforts. As more people got involved, competition would have increased
and it would have become harder for one man to get the same reward. The miners
developed better tools and then formed cooperatives to pool resources and get a
share of the gold at the end.
This
increased difficulty has prompted a surge of more powerful computing technology
to try to increase the likelihood of successfully mining the bitcoins. From one
man and his computer graphics card decoding blocks and earning a few bitcoins
to an entire network of miners using specifically designed hardware.
It has become a multi-million dollar mining industry all of its own. A couple of years ago the field-programmable gate array (FPGA) became a step towards a custom mining chip. Now the application-specific integrated circuit (ASIC) miner is one of the latest on the market. One small piece of hardware can be plugged into a computer’s USB port and crunch away. One of these things can be purchased for around 1 BTC or approx. $100.
At the other end of the market,
Butterfly Labs have created powerful
speed, encryption processors, which can set you back thousands of dollars.
For
some, mining is not cost-effective. Apart from the initial outlay for the
hardware, operating costs add up in Internet and electricity bills. As bitcoin
is a digital currency, a miner must be online for it to work and with some
people leaving their miners operating 24/7, electricity prices can create a big
dent in finances. The financial incentive depends on the exchange rates and
starts to diminish if the difficulty level reaches a point that the cost to run
a mining rig exceeds the value of the bitcoins in return.
The
chart below from blockchain.info shows how profit
margins have fluctuated over the past year.
The
constant hardware developments do mean it is advantageous to upgrade regularly
otherwise, your more primitive miner could be slogging away trying to mine a
block, which a newer, more powerful model can mine in half the time. The
winners in the mining game may well be the companies producing the mining
technology rather than the miners themselves.
So
then comes the question: why bother mining? For some it is still a feasible way
of generating some income and while there are still bitcoins out there to be
found in the digital ether, there will remain a dedicated network attempting to
release them.
The
future success of bitcoin relies heavily on people’s willingness to use it. It
is backed by the people; the network of miners, the owners and users of
bitcoins; the entire bitcoin community. Everyone who uses it has that invested
interest in not allowing bitcoin to fail and for this reason there will always
be an incentive to mine. When all the bitcoins are mined, we might be looking
at small transaction fees as a way to reward miners for keeping the blockchain
going and validating transactions. Currently less than 0.8% of mining revenue
is from transaction fees. But that is a good twenty to thirty years away and
right now there are still more than 9.5 million bitcoins up for grabs. Grab
your pickaxe…
By Louise @ Bitscan