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Project and event Time ago. TOP active today. Project and term of work. Admins on ISP total Projects whose administrators have recently registered on ISP. Best RCB. Find the best RCB. Latest insurances. Project and insurer. All projects under insurance. Partisans - rebranding. All partisans. Beware of fakes read. Dear friends! Welcome to Real Estate Investment read. All news. March 15, Farm Bitcoin. Incorrect status? Write to us. Paying 0 0. Waiting 0 0. Problem 0 0. Scam 0 0. Double spending is a scenario in which a Bitcoin owner illicitly spends the same bitcoin twice.
Though counterfeit cash is possible, it is not exactly the same as literally spending the same dollar twice. With digital currency, however, as the Investopedia dictionary explains, "there is a risk that the holder could make a copy of the digital token and send it to a merchant or another party while retaining the original.
If you were to try to spend both the real bill and the fake one, someone who took the trouble of looking at both of the bills' serial numbers would see that they were the same number, and thus one of them had to be false. What a blockchain miner does is analogous to that—they check transactions to make sure that users have not illegitimately tried to spend the same bitcoin twice. This isn't a perfect analogy—we'll explain in more detail below.
Only 1 megabyte of transaction data can fit into a single bitcoin block. The 1MB limit was set by Satoshi Nakamoto, and this has become a matter of controversy because some miners believe the block size should increase to accommodate more data, which would effectively mean that the Bitcoin network could process and verify transactions more quickly. In addition to lining the pockets of miners and supporting the Bitcoin ecosystem, mining serves another vital purpose: It is the only way to release new cryptocurrency into circulation.
In other words, miners are basically "minting" currency. For example, as of March , there were just under 19 million bitcoins in circulation, out of a total of 21 million. Aside from the coins minted via the genesis block the very first block, which founder Satoshi Nakamoto created , every single one of those bitcoins came into being because of miners.
In the absence of miners, Bitcoin as a network would still exist and be usable, but there would never be any additional bitcoin. However, because the rate of bitcoin "mined" is reduced over time, the final bitcoin won't be circulated until around the year This does not mean that transactions will cease to be verified. Miners will continue to verify transactions and will be paid fees for doing so in order to keep the integrity of Bitcoin's network.
To earn new bitcoins, you need to be the first miner to arrive at the right answer, or closest answer, to a numeric problem. This process is also known as proof of work PoW. To begin mining is to start engaging in this proof-of-work activity to find the answer to the puzzle. No advanced math or computation is really involved. You may have heard that miners are solving difficult mathematical problems—that's true but not because the math itself is hard.
What they're actually doing is trying to be the first miner to come up with a digit hexadecimal number a " hash " that is less than or equal to the target hash. It's basically guesswork. So it is a matter of randomness, but with the total number of possible guesses for each of these problems numbering in the trillions, it's incredibly arduous work.
And the number of possible solutions referred to as the level of mining difficulty only increases with each miner that joins the mining network. In order to solve a problem first, miners need a lot of computing power. Aside from the short-term payoff of newly minted bitcoins, being a coin miner can also give you "voting" power when changes are proposed in the Bitcoin network protocol. In other words, miners have some degree of influence on the decision-making process for matters such as forking.
The more hash power you possess, the more votes you have to cast for such initiatives. The rewards for Bitcoin mining are reduced by half roughly every four years. When bitcoin was first mined in , mining one block would earn you 50 BTC. In , this was halved to 25 BTC. By , this was halved again to On May 11, , the reward halved again to 6.
Not a bad incentive to solve that complex hash problem detailed above, it might seem. To keep track of precisely when these halvings will occur, you can consult the Bitcoin Clock , which updates this information in real time. Interestingly, the market price of Bitcoin has, throughout its history, tended to correspond closely to the reduction of new coins entered into circulation.
This lowering inflation rate increased scarcity and, historically, the price has risen with it. If you want to estimate how much bitcoin you could mine with your mining rig's hash rate, the site CryptoCompare offers a helpful calculator. Other web resources offer similar tools. Although individuals were able to compete for blocks with a regular at-home personal computer early on in Bitcoin's history, this is no longer the case.
The reason for this is that the difficulty of mining Bitcoin changes over time. In order to ensure the blockchain functions smoothly and can process and verify transactions, the Bitcoin network aims to have one block produced every 10 minutes or so. However, if there are 1 million mining rigs competing to solve the hash problem, they'll likely reach a solution faster than a scenario in which 10 mining rigs are working on the same problem. For that reason, Bitcoin is designed to evaluate and adjust the difficulty of mining every 2, blocks, or roughly every two weeks.
When there is more computing power collectively working to mine for bitcoins, the difficulty level of mining increases in order to keep block production at a stable rate. Less computing power means the difficulty level decreases. At today's network size, a personal computer mining for bitcoin will almost certainly find nothing.
All of this is to say that, in order to mine competitively, miners must now invest in powerful computer equipment like a graphics processing unit GPU or, more realistically, an application-specific integrated circuit ASIC.
Some miners—particularly Ethereum miners—buy individual graphics cards as a low-cost way to cobble together mining operations. Today, Bitcoin mining hardware is almost entirely made up of ASIC machines, which in this case, specifically do one thing and one thing only: Mine for bitcoins. Today's ASICs are many orders of magnitude more powerful than CPUs or GPUs and gain both more hashing power and energy efficiency every few months as new chips are developed and deployed.
Say I tell three friends that I'm thinking of a number between one and , and I write that number on a piece of paper and seal it in an envelope. My friends don't have to guess the exact number; they just have to be the first person to guess any number that is less than or equal to it. And there is no limit to how many guesses they get.
Let's say I'm thinking of the number There is no "extra credit" for Friend B, even though B's answer was closer to the target answer of Now imagine that I pose the "guess what number I'm thinking of" question, but I'm not asking just three friends, and I'm not thinking of a number between 1 and Rather, I'm asking millions of would-be miners, and I'm thinking of a digit hexadecimal number.
Now you see that it's going to be extremely hard to guess the right answer. If B and C both answer simultaneously, then the system breaks down. In Bitcoin terms, simultaneous answers occur frequently, but at the end of the day, there can only be one winning answer. Typically, it is the miner who has done the most work or, in other words, the one that verifies the most transactions. The losing block then becomes an " orphan block.
Miners who successfully solve the hash problem but haven't verified the most transactions are not rewarded with bitcoin. Here is an example of such a number:. The number above has 64 digits. Easy enough to understand so far. As you probably noticed, that number consists not just of numbers, but also letters of the alphabet.
Why is that? To understand what these letters are doing in the middle of numbers, let's unpack the word "hexadecimal. The decimal system uses factors of as its base e. This, in turn, means that every digit of a multi-digit number has possibilities, zero through In computing, the decimal system is simplified to base 10, or zero through nine. In a hexadecimal system, each digit has 16 possibilities. But our numeric system only offers 10 ways of representing numbers zero through nine. If you are mining Bitcoin, you do not need to calculate the total value of that digit number the hash.
I repeat: You do not need to calculate the total value of a hash. Remember that analogy, in which the number 19 was written on a piece of paper and put in a sealed envelope? In Bitcoin mining terms, that metaphorical undisclosed number in the envelope is called the target hash. What miners are doing with those huge computers and dozens of cooling fans is guessing at the target hash. Miners make these guesses by randomly generating as many " nonces " as possible, as quickly as possible.
A nonce is short for "number only used once," and the nonce is the key to generating these bit hexadecimal numbers I keep mentioning. In Bitcoin mining, a nonce is 32 bits in size—much smaller than the hash, which is bits. The first miner whose nonce generates a hash that is less than or equal to the target hash is awarded credit for completing that block and is awarded the spoils of 6. In theory, you could achieve the same goal by rolling a sided die 64 times to arrive at random numbers, but why on Earth would you want to do that?
The screenshot below, taken from the site Blockchain. You are looking at a summary of everything that happened when block No. The nonce that generated the "winning" hash was The target hash is shown on top. The term "Relayed by AntPool" refers to the fact that this particular block was completed by AntPool, one of the more successful mining pools more about mining pools below. As you see here, their contribution to the Bitcoin community is that they confirmed 1, transactions for this block.
If you really want to see all 1, of those transactions for this block, go to this page and scroll down to the Transactions section. Source : Blockchain. All target hashes begin with a string of leading zeroes. There is no minimum target, but there is a maximum target set by the Bitcoin Protocol. No target can be greater than this number:. The winning hash for a bitcoin miner is one that has at least the minimum number of leading zeroes defined by the mining difficulty. Here are some examples of randomized hashes and the criteria for whether they will lead to success for the miner:.
To find such a hash value, you have to get a fast mining rig, or, more realistically, join a mining pool—a group of coin miners who combine their computing power and split the mined Bitcoin. Mining pools are comparable to Powerball clubs whose members buy lottery tickets en masse and agree to share any winnings.
A disproportionately large number of blocks are mined by pools rather than by individual miners. In other words, it's literally just a numbers game. You cannot guess the pattern or make a prediction based on previous target hashes. At today's difficulty levels, the odds of finding the winning value for a single hash is one in the tens of trillions.
Not great odds if you're working on your own, even with a tremendously powerful mining rig. Not only do miners have to factor in the costs associated with expensive equipment necessary to stand a chance of solving a hash problem, but they must also consider the significant amount of electrical power mining rigs utilize in generating vast quantities of nonces in search of the solution.
All told, Bitcoin mining is largely unprofitable for most individual miners as of this writing. The site CryptoCompare offers a helpful calculator that allows you to plug in numbers such as your hash speed and electricity costs to estimate the costs and benefits.
Source : CryptoCompare. The miner who discovers a solution to the puzzle first receives the mining rewards, and the probability that a participant will be the one to discover the solution is equal to the proportion of the total mining power on the network. Participants with a small percentage of the mining power stand a very small chance of discovering the next block on their own.
For instance, a mining card that one could purchase for a couple of thousand dollars would represent less than 0. With such a small chance at finding the next block, it could be a long time before that miner finds a block, and the difficulty going up makes things even worse.
The miner may never recoup their investment.