Bitcoin forgets the key

1. I'll give you my address (address). You can find my zip code (public key). You can write to me with my zip code (public key) + address. The mail will be sent to my mail cabinet. I'll open the mail cabinet (private key) with the key I have. The key of express cabinet is stored in my wallet (wallet)
1. The mail cabinet is stolen (the database is stolen)
2. The key is stolen (the private key is stolen)
3. Knowing my home address (the public key is stolen), the lock of the mail cabinet is opened violently (the private key is cracked violently).

2. First of all, let's talk about the background. The basic principle of bitcoin "account" is key public key address. You can roughly understand it as "key box box number". Now is to start from the box number or box to crack the key
there are basically two kinds of attacks, one is dictionary attack, the other is brute force attack
dictionary attack is to use common passwords and their simple variants as keys one by one. As long as your pass phrase is not hard enough, the possibility of successful attack is very high. So if you want to use this, you need to popularize the knowledge of cryptography first, and don't think it's very safe to add a long password
if you don't use the wallet generated by pass phrase, you can only crack it violently, which is equivalent to enumerating all the possible keys. At present, this is impossible, even if the electronic computer is becoming more and more powerful. However, quantum computer can do it theoretically, but don't worry too much. If such a powerful quantum computer comes out, it will not only endanger bitcoin
at the same time, bitcoin has a second layer of protection: if an address only accepts bitcoin but does not output it, its public key is confidential, that is to say, no one else can see the box, only the box number. At present, the process of decing the box from the box number can't even be done by quantum computer. In other words, if there is a quantum computer, bitcoin has a last line of Defense: it's temporarily safe to transfer your money to a new address
finally, some time ago, the wallet generated by the Android client was attacked because of a bug in the underlying random number generator. In fact, this function is not random securerandom, which Google quickly admitted and fixed. It's hard to say whether this kind of thing will happen again, but I don't think we need to worry too much.

3. Common measures to deal with the loss of private key and password:
1. Delete the wallet by mistake
this is the same operation as I do. What should I do in case of this kind of thing? In fact, as long as you remember the private key, download a wallet again, import the private key and reset the password of the wallet
2. The mobile phone is missing or broken
if your mobile phone is stolen or broken, as long as the private key or mnemonic word is still there, you can download a wallet again, import the private key (or mnemonic word) and recreate the wallet
3. The private key is forgotten, but the mnemonic (or JSON file) is still there
if your private key is lost, but the mnemonic (or JSON file) is still there, don't worry, mnemonic can help you retrieve the private key,
4. The private key is forgotten
the wallet hasn't been deleted. If your private key is forgotten, but the wallet is still on your mobile phone, it's very easy to do, You just log in with your password, enter your wallet, and back up your private key
5. The private key, password and mnemonic words have been lost
sorry, no one can help you
6. Forgotten password or wrong input
this is the same as some other apps that we usually log in. If we forget password or input error several times, click forget password to retrieve it. Back to the decentralized wallet, we need to use the private key or mnemonic words to import the wallet to reset the password
7. Forget the mnemonic words
import the wallet with the private key and back it up again
8. Keystore forgotten
if your wallet is not deleted, this is the same way as if your private key is forgotten but your wallet is not deleted, that is, log in with your wallet password and make a new backup; But if your wallet is deleted, that is, it is unloaded, you need to import the wallet with mnemonic words or private key to backup the keystore again!

4.

According to Chaina alysis, a research firm, up to 20% of the existing bitcoin has disappeared forever. At the time of the study, about 3.8 million bitcoins could never be retrieved. In this article, we will explore all possible ways to lose bitcoin

1. Cryptocurrency hackers

the hacker behavior of cryptocurrency exchange is the main reason for the loss of bitcoin. Exchanges are a hot target for cyber criminals, accounting for 27% of cyber attacks in 2018. Mt. GOx was the first high-profile cryptocurrency hacker, but since then, many major exchanges have been hacked, including bitfinex, bitstamp and, more recently, cryptopia, the cryptocurrency exchange in New Zealand, which lost 9.4% of its total positions

Malware

the malware on torrent website and Google play store are used to steal passwords from vulnerable categories. For example, there is a malware clipper that uses users' behavior of ing and pasting wallet addresses to steal passwords. For example, if you send BTC to an address, you usually and paste the address, because it is a long string of random characters, clipper malware will exchange wallet addresses, which means that when you paste, you will send encryption to the wrong address

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. The private key is a secret data block that proves that you have the right to consume bitcoin from a specific wallet. It is implemented through a cryptographic signature. If you are using wallet software, your private key is stored in your computer; If you are using an online wallet, your private key is stored on a remote server. Don't disclose private keys, because they allow you to consume the bitcoin in the corresponding bitcoin wallet
digital currencies such as Ruitai, doggy and Wright all have private keys.

7. See if you remember your account number, password and bitcoin private key
if you still remember the account number and password of the platform where you bought the coin, you can log in, check your coin, and record the private key and public key, so that you won't lose them.

8.

With more and more cases of bitcoin becoming rich, many people realize that the appreciation space behind bitcoin is very huge. Many people are annoyed that they didn't catch the train of becoming rich. Compared with the common legal currency in life, bitcoin is a virtual digital currency. Since its birth in January 2019, the price of bitcoin has increased from US $0.0025 to US $0.0025, After ten years of development, it has successfully broken through to US $31000, and the soaring momentum has not stopped{ RRRRR}

most of them come from bitcoin mined in the early stage of technology. Many people think that these bitcoins are worthless, and they are unwilling to spend time to save them, so they are graally forgotten by themselves, and even many people have long forgotten that they own bitcoin. It must be that those who lost them because they had no hope for bitcoin should regret it now, I can only comfort myself that I have no predestined relationship with sudden wealth

9. Memory. Graphics card and CPU transmission. The previous set is also integrated in the north bridge. But now the north bridge is no longer. All integrated in the CPU