Bitcoin unconfirmed transaction

1. bitcoin was born in a paper in 2008
a person signed by Nakamoto Tsui has put forward a revolutionary idea: let's create a currency that is not controlled by the government or anyone else! This idea is crazy: there is no asset support behind a string of figures, and no one is responsible for it. How can anyone accept it when you pay it to the other party as money
Merkle tree
looks like a binary tree, but this is the lower two nodes. Take the hash value to get the upper node. Just remember the root node to detect whether the whole tree has been tampered
the root hash value is stored in the block header, and the transaction process is stored in the block body. All nodes include block header and block body, but light nodes (such as bitcoin wallets on mobile phones) only include block header. This tree can prove that a transaction has been written into the blockchain
3. Consensus agreement
two issues should be paid attention to in decentralized currency:
1. Who can issue digital currency: mining
2. How to verify the legitimacy of transactions: blockchain
double spending attack
double spending attack is a major challenge of digital currency
all transactions in bitcoin have input and output. Where does bitcoin come from and where does it go
under normal circumstances, there may be two bifurcations, because two nodes obtain the bookkeeping right at the same time, and the two nodes package the block and calculate the random number at the same time. At this time, the two bifurcations will coexist temporarily until one of the blocks finds the next block first, which becomes the longest legal chain, and the other one is discarded<

Sybil attack
a malicious node keeps generating accounts. If the total number of accounts exceeds half of the total accounts, it obtains the control of the blockchain

consensus protocol in bitcoin
some nodes are malicious, and most nodes are good

idea 1: pack some transactions into blocks as candidate blocks, let each block vote, and write them into the blockchain if they pass

No, because some malicious nodes have been publishing blocks containing malicious transactions, and they have been voting and occupying resources. And some nodes don't vote<

idea 2: vote not by the number of accounts, but by computing power. Each node can generate legal transactions and put them into the block. These nodes start to try random numbers until H (block header) ≤ target is found, then this node has the right to account

the only way to generate bitcoin
coinbase transaction. There is no need to point out the source of the currency. If you have the bookkeeping right, you will get a reward< br />
50BTC-> 25BTC-> 12.5btc, the reward will be halved for every 210000 bitcoins

the process of bitcoin competing for bookkeeping rights is called mining. The node competing for bookkeeping right is called miner.

2. "Bitcoin original team created transaction currency" is pure false information. Transaction currency was developed by a foreign operation team, but no one knows the inventor as well as the creator of bitcoin, Nakamoto. The biggest advantage of transaction currency is that you can use it in other currencies without wasting resources

as for whether it is worth investing, I don't know, but I don't recommend investing in Shanzhai currency. The risk is much greater than investing in bitcoin.

3. Go to the bitcoin blockchain website to query the transaction data on the chain

4. It is often said that you can send bitcoin to any corner of the earth for free. Generally, you can transfer bitcoin for free, but in some cases, you have to pay transaction fees to complete the transfer. In version 0.8.3 bitcoin wallet, the default is 0.0001 bitcoin transfer fees. This service charge is awarded to miners to encourage them to continue mining and provide enough computing power for bitcoin to ensure the security of bitcoin network. At present, the main income of miners is to get 25btc reward by creating new blocks, but this reward is halved every four years. As time goes on, bitcoin transaction fee reward will graally replace the reward for creating new blocks. Under what circumstances do you need to pay the handling charge? How much does bitcoin charge? What is the handling charge? Bitcoin system has a series of network rules, including fee rules, which are "what the client should do". When you use bitcoin client (wallet, bitcoin QT) to send bitcoin, the whole process is roughly divided into the following steps:
1. Prepare the bitcoin you want to send. The client is responsible for collecting the balance of bitcoin in your wallet (bitcoin QT) to prepare for payment, because every bitcoin you receive is stored in your wallet until you spend it. If you receive two payments from 3btc and 2btc, their records in the wallet are independent of each other, that is, a 3btc and a 2btc, rather than merging them into 5btc (the wallet only records transaction details and does not merge the balance, but you can see the total balance on the interface of the wallet). As time goes on, many bitcoins of different amounts will accumulate in your wallet, So when you send bitcoin, the wallet has to decide which bitcoin is the most suitable for this sending. The bitcoin you get in a transaction is called "inputs" and the bitcoin you spend is called "outputs". There are multiple inputs and outputs in your wallet
2. If your outputs are less than 0.01btc (including the fund changes inside your wallet), you have to pay a handling charge of 0.0001, even if you transfer it to yourself. The wallet has an established rule when preparing your payment amount, that is, when preparing the payment amount in many inputs, try to avoid the amount change less than 0.01btc (for example, if you want to pay 5.005btc, the wallet should choose 3 + 2.005 or 1 + 1 + 3.005 instead of 5 + 0.005)
3. The larger the amount, the higher the age, and the higher the priority. If the amount you send is too small or your bitcoin has just been mined, then your transfer is no longer free. Each transaction will be assigned a priority, which is determined by the degree of currency, the number of bytes and the number of transactions. Specifically, for each input, the client will first multiply the number of bitcoins by the time they exist in the block (currency age, age), and then divide all the procts by the size of the transaction (in bytes). The calculation formula is: priority = sum (input)_ value_ in_ base_ units * input_ age)/size_ in_ If the calculation result is less than 0.576, then the transaction must pay the handling fee. If you do have a large amount of small input and want to transfer it out for free, you can add a large amount of bitcoin with a large age, which will increase the average priority, so that you can transfer out bitcoin for free
4. Charge per kilobyte. At the end of the transfer, the client will detect the size of the transfer (in bytes). The size generally depends on the amount of input and output. The calculation formula is as follows: 148 * input amount + 34 * output amount + 10. If the size of the transfer exceeds 10000 bytes, but the priority meets the free standard, you can still enjoy the free transfer, Otherwise, there will be a handling charge. The cost of 1000 bytes is 0.0001btc by default, but you can also add it in the client. Open the tab "settings & gt; Options & gt; The main purpose is to adjust the handling charge. If the service charge you are setting is less than 0.0001, BTC is calculated as 0.0001.

5. This kind of thing also believe ah, recently the RMB appreciation, you know, also replace the RMB nonsense are made up, who told you, scold him a liar, let him go

6. It can't be displayed at the same time. This is the bad part. Shuangcai usually needs to switch from time to time

7. Compared with the transaction on the chain, the utxo set of BCH network is also growing. The growth of utxo increases with the adoption rate, and the scale of utxo has soared since September 2018
utxo is the abbreviation of unspent transaction output, and transaction act is pronounced as X. Utxo is the first specific technical solution adopted by Nakamoto in bitcoin. In the design of bitcoin, there is no account concept

8. Recently, it has become very clear that the US government wants more information about the decentralized virtual currency like bitcoin. In a recent budget approved by the committee, congressional representatives asked the FBI to provide them with a report. The title of the bill is money laundering. The committee understands that bitcoin and other similar forms of P2P digital currency are potential tools for criminals, terrorists or other illegal organizations and indivials to engage in illegal money laundering and fund transfer. News reports say bitcoin has been used to help finance the travel and activities of fugitives. " Translator: is that Snowden—— House Appropriations Committee. In the same week, a Senate committee sent a letter on homeland security to Janet Napolitano's secretary of homeland security. The letter mentioned the need for a strategic framework to deal with bitcoin. However, what this letter clearly seeks is a guidance rather than the idea of stifling legislation that many people fear. With the emergence of any new technology, the federal government must be sure that any potential threat can be dealt with quickly; However, we must also ensure that we do not take reckless and ignorant actions to stifle valuable potential technologies—— The U.S. Senate Homeland Security and government affairs committee concluded with a virtual currency inquiry from the New York State Financial Services Administration. They made it clear in the letter that they meant to find a way to operate in the new financial environment, and that the rules for ordinary legal currency may not be applicable to currencies like bitcoin. As fortune reported, this has led to many subpoenas being sent to 22 bitcoin related companies in New York, so that the authorities can learn more. If virtual money is still a virtual Wild West, for drug dealers and other criminals. This will not only threaten the national security of our country, but also threaten the existence of the virtual currency instry itself as a legal commercial enterprise—— The New York State Financial Services Authority's recent ruling on money laundering by a US court in DEXA has given the case that bitcoin is a currency. That case actually has something to do with bitcoin savings & trust, which is accused of Ponzi fraud. A clear conviction that bitcoin is indeed a currency means that this is a judicial investigation. Authorities already know that tracking bitcoin transactions is difficult. That's the key reason why illegal drug markets like the Silk Road and Atlantis operate only with bitcoin. According to a recent report, the website has deployed a system to further anonymize bitcoin that flows to drug sellers on the site. This would make it much harder for authorities to track bitcoin than real dollars. Although it is reported that bitcoin has been found in a drug-related case by the judiciary. This means that they are not completely ignorant. However, if we consider that criminals generally take a step ahead and adapt to the authorities, and there are policies above and Countermeasures below, the federal government will be in a serious disadvantage. Many bitcoin startups have received millions of venture capital. The survey concted in New York has cast a shadow over the sustainable development of the bitcoin instry in the United States. While bitcoin startups in the US may feel threatened by regulators, there may be loose regulation elsewhere. Even if that's true, America is still the best place for startups to get venture capital. VCs like to invest in technology companies in the bay area because it is a hotbed of technical talents and capital. Can this be replicated elsewhere? It's still going to take a while to know. Bitcoin is very popular in the financial sector of San Francisco Bay area and New York. It's scary to think about how expensive it would be to fully regulate bitcoin companies, whether you run a bitcoin exchange, a bitcoin mobile wallet, or a mining company. All of these kinds of operations are transferring money, as the state court has ruled. Any company that handles bitcoin for its customers will be transferring money. The balance that economic impact regulators need to keep is to allow innovative financial technologies like bitcoin to stimulate the economy, while not allowing these companies to be overwhelmed by inexplicable fees and regulations. California has done this, and it has made complex capital transfer regulations for local companies, so that those particularly complex high-tech companies, such as Facebook, who have their own virtual currency, choose to ignore the law. Btccompanies: companies that have been subpoenaed. List of companies that have been subpoenaed. Federal legislators won't let any bitcoin slip through the cracks. There are too many bitcoin crime crises that need to be thwarted by the government to complete. It's interesting to look at the companies that have been subpoenaed: most of them are well-known mature companies. There are a lot of VCs on the list. Standard wealth bitcoin is not a bank. He doesn't have to deal directly with regulators to handle the money. There's not much that can stop an American bitcoin company from operating. As the International Monetary Fund recently wrote, "e to the transnational and decentralized nature of bitcoin, bitcoin as an unregulated virtual cash brings a series of difficult legal problems." The open source of the dollar is an interesting concept. Standard wealth is a company that is currently building something similar to the dollar's application program interface (API). The idea is to make banking services easier for businesses or organizations that pay high banking fees. There's more to show, though. No matter what standard wealth does, an innovative project like this, the US government will always have the highest authority over the US dollar. It's an economic weapon. It's 61% of the world's reserve currency. Protecting this is part of the purpose of bitcoin legislation, even if it actually makes the banking instry more transparent, like standard wealth. Less bitcoin fraud. The U.S. government doesn't want another bitcoin bank & trust. Trendon shafers, the owner of the fake bank being sued, has made the government understand how easy it is to get 60 million dollars from ordinary people who want to invest and make money. So the government doesn't want people to use bitcoin as a trading medium to buy drugs that are sent to them anonymously. They may be able to control any kind of bitcoin enterprise, but bitcoin is not liberty reserve after all. He's decentralized. There are no central operators that the federal government can talk to. Bottom line: can the US government control bitcoin? They believe that bitcoin is an advanced form of money and may be too powerful in the hands of criminals. But it's still a question whether they can control it as much as legal money. However, the government needs to start thinking about what to do before bitcoin can be developed into daily life. How do you think the government, especially the US government, will regulate bitcoin?

9. Trading currency is the same source of bitcoin. It can be launched on the nkle exchange a few years ago and has huge development space