Blockchain Watch Network mentioned in the article "What is a blockchain" that in the blockchain world, everyone has two unique virtual keys: a public key and a private key.
The "public key" can be simply understood as a bank card, which can be sent to the counterparty. The bank card number is equivalent to the "address" used for bitcoin transfer.
More technically, the public key is a 65-byte string. How long is it? 130 letters and numbers are piled together. If the public key is too long, the transaction will be very troublesome at first, and then why must the true content of the public key be exposed? It's like showing your bank card to people everywhere. Therefore, the address we see now is a shorter public key generated by the digest algorithm.
The other party can only give you money if they know your address; Moreover, anyone with your address can find out how many times this wallet address has been traded (no transaction), how many bitcoins have been received in official website at Blockchain.info (total received) and how many bitcoins are left in the wallet (final balance), as shown below:
"Private key" is like killing a bank card password that you can't tell others. It is a string of 256-bit random numbers. Because IT is particularly inhumane for non-IT users to remember this binary private key with full screen 0 and 1, we have to deal with this large string of private keys, and finally the string of private keys starting with 5/k/L is presented to us.
The relationship between public key, private key and address is:
1) private key → public key → address
The private key generates a unique corresponding public key, and the public key generates a unique corresponding address;
2) private key encryption and public key decryption
In other words, A encrypts the transaction information (digital signature) with the private key and B decrypts the digital signature with A's public key.
Among them, private key is extremely private. If you send the private key to others, start writing a novel now. The name has been thought of for you. It's called farewell to bitcoin.
If it is a big coin circle like Teacher Li Xiaolai (there are hundreds of thousands of BTCs online), it is strongly recommended to use a cold wallet (offline wallet) and store it separately; The rich man on TV has his own safe in the bank, so you can refer to it if you have the conditions.
At that time, the above method was the one with the highest safety factor. But as the successor of leek, let's assume that we only used idle funds to hold a small number of bitcoins at first, such as less than five. Then, the cold wallet, which costs thousands of dollars and is complicated to operate, is a bit of a knife to kill the chicken; Therefore, the blockchain observation network limits the choice to two items: redemption and light wallet:
If you buy (a very small amount) bitcoin on the trading platform, you can continue to exist on the exchange without mentioning it. This method is most suitable for beginners in the currency circle. Before we have a deep understanding of the story behind each cryptocurrency, we are always curious. Bitcoin placed on the exchange can be traded directly, and the transaction is simple and fast, without the guidance of a digital wallet; On the other hand, the currency on the platform is complete, which can satisfy our early adopters' psychology and is convenient to try at any time.
Moreover, large-scale exchanges such as Huobi and Bian (which have been fenced) are not only much safer than some small platforms dedicated to harvesting leeks, but also simple to operate and can be used quickly. Just keep your account and password (if the security level is higher, turn on Google's secondary verification), and leave the rest to the platform.
It is worth noting that the assets deposited in the exchange are not entirely their own, but are lent to the platform. The figures we see in the assets column are equivalent to the IOUs that the platform borrows money from us. Besides, the trading platform itself is not decentralized. If the security measures are not in place, the user's account password may be obtained by hackers.
A light wallet is relative to a "full node" wallet.
All-node wallets, such as Bitcoin core, need to synchronize all blockchain data at runtime, occupying a considerable memory space (at least 50GB at present) and completely decentralized;
Although the light wallet also depends on other nodes on the bitcoin network, it only synchronizes the transaction data related to itself, which basically realizes decentralization and improves the user experience.
According to different equipment types, we divide light wallets into:
1)PC wallet: suitable for computer desktop operating system (such as Windows/MAC OS/Linus);
2) Mobile wallet: suitable for Android and iOS smart phones, such as Tabby wallet (Ethernet also has PC);
3) Online wallet: accessed through a browser, such as the web version of the blockchain mentioned above.
The operation of light wallet is relatively simple, and it is generally obtained free of charge. When applying for a wallet, the system will generate a private key. Prepare to knock on the blackboard!
1) Don't take screenshots in your mobile phone;
2) Don't send private key information to anyone;
3) It's best to write down (several copies) by hand and hide it in the safest place you think.
In short, whoever owns the private key of the wallet will have absolute control over the wallet. As long as you have the private key, Bitcoin will never be lost.
Finally, as ordinary investors, we don't need to do much:
1) Take a snack and don't lose your mobile phone. After all, losing it is risky for the bitcoin wallet in your mobile phone;
2) Don't delete the wallet application on the device in a hurry. Unless you decide not to use this wallet, it will be very troublesome in the future;
3) Set a complicated password (see point 1 for reasons), and remember carefully that this is a skill left after losing the private key.
For friends who can't remember the password and are too lazy to back up the private key scientifically, put the money in the bank.