Bitcoin Cold Chain Wallet

1.

Fire coin is a bitcoin trading platform. As of the end of 2016, the accumulated turnover of fire coin reached 200 billion yuan

bitcoin is a virtual encrypted digital currency in the form of P2P

Bitcoin is different from all currencies. Bitcoin does not rely on a specific currency institution. It is generated by a large number of calculations based on a specific algorithm. Bitcoin economy uses a distributed database composed of many nodes in the whole P2P network to confirm and record all transactions, and uses the design of cryptography to ensure the security of all aspects of currency circulation. The decentralized nature and algorithm of P2P can ensure that it is impossible to artificially manipulate the value of bitcoin through mass proction

extended information:

fire coin business

1. Fire coin global station, headquartered in Singapore, provides digital asset trading and investment services

2. The digital asset trading platform based on Korean won provides digital asset trading services

3, China, has become a platform for information and research in vertical chain of block chain, providing regional chain technology research and application information for Chinese mainland users, and integrates services such as instry consultation, research and ecation training. p> The company is headquartered in Beijing, China, providing digital asset management services and user experience

2. In order to make it easier for new people to understand, sister coin will use some metaphors. Although she is not strict, she will understand better
the private key is like your bank card password
the address of bitcoin wallet is like your bank card
as long as you have the bank card and password, anyone can withdraw money from ATM
the address of bitcoin wallet is public, which means that everyone else has your bank card, so your bank card password (private key) becomes very important at this time
once your key is disclosed, others can transfer your bitcoin

Internet search: "sister coin teaches you bitcoin" or "sister coin" find me, share more exquisite content ~!

3.

The private key of bitcoin wallet cannot be viewed online. Bitcoin exists on the platform. To download core or classic is the real wallet, and then you can view it

[description of private key of bitcoin wallet]:

1. Wallet encryption refers to automatically encrypting and storing the wallet with private key. The official bitcoin client supports wallet encryption since version 0.4.0. The encrypted wallet will prompt you to enter your password every time you pay. If the password is wrong, the client will refuse to pay

2. If you replace it with the earliest backup wallet (wallet. DAT), you can still trade normally. Considering the principle of bitcoin, it can be concluded that as long as there is a private key (wallet), you can prove that you are the legitimate owner of the wallet. No matter whether you encrypt or delete the wallet (the core is the private key corresponding to an address), you can't deny it

3. When backing up the bitcoin wallet, you should also pay attention to the existence of bitcoin payment change mechanism (for example, if you send 50 BTC in a complete 100 BTC to an address, the system will send 50 BTC to the other party's address, and return 50 BTC to a new address of your client, which will not be directly displayed in your address list)

4. After sending bitcoin to other addresses 100 times or using 100 different addresses to receive bitcoin, please back up your wallet again, otherwise the returned and received bitcoin will be lost forever. In addition to encrypting wallets, users can also generate offline paper wallets and brain wallets

4. 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.

5. It refers to offline wallet. Users usually send and receive bitcoin by using offline bitcoin wallet address, and then confirm signature by using wallet private key offline. Therefore, hackers are unable to steal the private key of cold wallet. Because there is a link to confirm the signature offline, bitcoin cold wallet is not as convenient as hot wallet.

6. A cold wallet is an offline wallet. There is a hardware cold wallet, which is similar to a U disk. Another way is to use a computer or mobile phone that is not connected to the Internet to back up the bitcoin wallet files, install them offline and store them in it! Remember to the key and mnemonic words of your wallet and store them.

7. Elizabeth II, Isle of man, 1994

8. There is no such word, only zebra, which means zebra
zebra is the general name of zebra subgenus (scientific name: hippotigris) and zebra subgenus (scientific name: dolichohippus), which is a common equine animal in Africa. Zebras are named for their protective stripes, which are different from each other
this species is named zebra by famous travelers and naturalists. The earliest specimen sent to the British Museum is from South Africa. Zebra stands about 135 cm, 54 inches across the shoulder, weighs about 700 pounds, has a horse like appearance, no droop, and is typically characterized by its black nose and straight mane on its neck. The male is slightly larger than the female. There is a narrow dark stripe on the back, extending from the top of the back to the tail of the mane. The texture of the female is wider
zebra is an African specialty. The mountain zebra of South Africa is densely covered with wide black stripes except the abdomen, and the male has drooping flesh in the throat. Common zebra of Eastern, central and southern Africa with or without stripes from legs to hooves. The alt zebra is about 2.7 meters long. Its song sounds like a wild goose. Only its head, shoulder and nape are striped. Its legs and tail are white. It has a dark dorsal line. East Africa also proces a type of zebra, the largest, ears long (about 20 cm) and wide, narrow and dense stripes, so it is also known as the zebra with fine stripes
zebra distributed in Botswana, Democratic Republic of Congo, Ethiopia, Kenya, Malawi, Mozambique, Namibia, Rwanda, Somalia, South Africa, Sultan, Swaziland, United Republic of Tanzania, Uganda, Uganda, Uganda. It is rarely distributed, mostly in Africa
body length 200-240 cm, shoulder height 120-140 cm, tail length 47-57 cm, weight 350 kg. In addition to the abdomen, the whole body is covered with wide black stripes, which has a protective effect. It is widely distributed in eastern, central and southern Africa and inhabits in the tropical grassland with abundant water and grass. Generally, they live in a small group of 10-12 headed by an alt male, sometimes mixed with other animals such as antelope, takin, impala and ostrich. When there is a shortage of food, large groups of people can migrate. There are several subspecies, such as the zebra
the vowel e pronounces the long vowel / I / in the stressed open syllable. When pronouncing, the tip of the tongue is close to the lower teeth, the front of the tongue is raised very high, but does not touch the upper jaw, there is no friction, the gums are close to each other, and the lip shape is flat. This sound appears at the beginning, middle and end of the word, For example:
even number of
meter meter
fever
zebra
he he (main case)
we (main case)
me (guest case)
be
hope I can help you solve your doubts.

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