Introduction to virtual currency Teaching
From 2015 to 2017, the price of bitcoin increased from more than $100 to $17000, a 100 fold increase. Today, the market value of various numerical currencies is more than 700 billion US dollars. The myth of their benefits is not nonsense
but there are many things behind the chaotic digital currency. You may ask why air currency can be listed on the stock exchange? It's very simple. The exchange also has to charge a part of the fee. Raise the price and then sell it to make money. So the question is, how to identify air currency
first of all, you need to look at the projects behind the digital currency and see what their team background is. Generally speaking, teams without experience in the instry tend to earn money, but how much experience do they have? It is better to be able to participate in the construction of Ethereum and bitstock communities. Such a team is often more reliable. This requires investors to have a certain screening ability to identify good or bad
secondly, there is no way to implement many projects. How can we identify them? In addition to the ability of the team, we also need to see the feasibility, which requires us to systematically learn the knowledge of bitcoin and blockchain. For example, Zhu Jiawei, the COO of fire coin network, learned the blockchain from 0 to 1, and clearly described the development process of bitcoin and blockchain in the form of audio and text. Besides, don Tapscott and Alex Tapscott's "blockchain revolution" are worthy of careful taste P>
moreover, the bubble of digital money is very large nowadays. In the bubble, it is not difficult to make money, but the key is not to be greedy. Long term holding is not good, but it can be operated in a short term. You can make money if you want. However, the key is that people are all profit-making and greed is their nature. Therefore, many people do not accept what they see. They originally made money, but later they lost everything. The gain is not worth the loss. Therefore, it is necessary to control greed
1. Whether this kind of currency has a good application scenario planning, such as Ruitai currency and thousand gold card
2. Whether it can be traded at any time and whether there is a trading platform
3. Whether the information of the development and operation team is open and transparent
4. Direct currency, subscription currency, split currency and compound currency are recommended.
the nature of decentralization comes from the blockchain technology using distributed ledger<
Chinese name
cryptocurrency
foreign name
cryptocurrency
domain
blockchain
fast
navigation
national digital currency blockchain refer to
cryptocurrency other than bitcoin
cryptocurrency other than bitcoin, also known as Shanzhai currency and competitive currency (English: altcoin), part of which is generated by referring to bitcoin ideas, principles and source code, Virtual currency similar to bitcoin has more than 800 cryptocurrencies in circulation
from February to April 2017, the proportion of Shanzhai currency in the total cryptocurrency market value increased from 15% to nearly 40%
because bitcoin itself does not have an authoritative issuing institution and state power to maintain its authority and uniqueness, bitcoin and its imitators can only get along equally, although it is the earliest virtual currency, also the most famous and popular
keep the private key with symmetric encryption. Symmetric key algorithm means that both encryption and decryption use one key. The encryption methods we usually use are symmetric encryption, such as WinRAR encryption, bitcoin QT encryption of the private key file is also using the symmetric encryption algorithm. The commonly used symmetric encryption algorithms are AES, DES, RC4, RC5 and so on. Symmetric encryption requires users to set relatively complex keys to prevent brute force cracking. Go to top method 1 uses bitcoin QT to encrypt the private key wallet. In the command mode, we can use the encryptwallet command to encrypt the wallet. For the usage of command mode, please refer to the basic teaching of bitcoin: how to use the private key of paper wallet. This is the most simple and effective method of private key encryption. However, when the walletpassphrase command is used to decrypt the wallet, the key will be read into the computer memory, so it is possible for the attacker to obtain the key. Encryption command: encrypt wallet yourpassword decrypt wallet command: walletpassword yourpasswordtimeout change password command: walletpassword exchange oldpasswordnewpasswordgo to top method 2, use AES encryption provided by blockchain. Blockchain provides users with private key file encryption service based on AES algorithm. Users can download the encrypted file and save it properly
go to top method 3 uses TrueCrypt, a third-party software, to encrypt the key file, which is also recommended by the editor. TrueCrypt is open source and free, with high software maturity, and supports two factor authentication and whole hard disk encryption. In addition, FBI personnel have suffered losses on TrueCrypt, so they have a good reputation. The FBI has admitted defeat in attempts to break the open source encryption used to secure hard drives seized by Brazilian police ring a 2008 investigation.
the bureau had been called in by the Brazilian authorities after the country's own National Institute of Criminology (Inc) had been unable to crack the passphrases used to secure the drives by suspect banker, Daniel Dantas.Brazilian reports state that two programs were used to encrypt the drives, one of which was the popular and widely-used free open source program TrueCrypt. Experts in both countries apparently spent months trying to discover the passphrases using a dictionary attack, A technique that involves trying out large numbers of possible character combinations until the correct sequence is found. Users who use it must keep the key in mind. If you forget the key, no one can recover your encrypted files
TrueCrypt, the official website of TrueCrypt, uses the asymmetric encryption method to keep the private key of the document. The asymmetric encryption method uses the form of public key and private key to encrypt the file. Users can encrypt files with public key and decrypt files with private key. Common asymmetric encryption algorithms include RSA, ElGamal, ECC and so on. The advantage of asymmetric encryption is that the complexity of the key is generally very high, which can effectively prevent violent cracking. The disadvantage is that there is a certain threshold, which is not suitable for ordinary users. Go to top method 1. Indivial users can consider using RSA for encryption. First, you can create a public key and a private key. Click here to generate the key. After keeping the public key and private key properly, you can encrypt and decrypt with the public key. Click here to encrypt and decrypt. RSA public key and private key generation process RSA public key and private key generation process randomly choose two large prime numbers P and Q, P is not equal to Q, calculate n = PQ. According to Euler function, R is obtained= φ( N) = φ( p) φ( q) = (p-1) (Q-1) select an integer E which is less than R and obtain the mole inverse element of e with respect to mole R, named D If and only if e and R are coprime, the records of P and Q are destroyed N. E) is the public key and (n, d) is the private key. Second, we can use PGP (pretty good privacy) tool to encrypt files. PGP encryption allows each public key to bind to all information of a user. Compared with RSA, the function of PGP is more perfect and reliable. However, with the upgrade of Pgp, new encrypted messages may not be decrypted by the old PGP system, so users should be familiar with PGP settings before using PGP. There are many PGP encryption tools on the Internet, so the editor will not list them
Introction to Pgp in Wiki PGP online encryption and decryption system PGP command FAQ advanced method to keep the private key. The above ways to keep the private key are very common. An experienced attacker may still get the user's private key file. For more advanced private key storage methods, please refer to the advanced teaching content of bitcoin in the future.