Blockchain statements
5. There is no project white paper, or the quality of the white paper is poor, all of them are "fake" blockchain projects
6. There is no open source, all of them are "fake" blockchain projects
7. All of them are "fake" blockchain projects that claim to be the general points of XX enterprises
8, The above nine points are applicable to more than 99% of the current blockchain projects. The following are some auxiliary knowledge points for strengthening judgment
first, if there is no venture capital investment, it is likely to be a "fake" blockchain project
Second, if there is no enterprise mailbox, it is likely to be a "fake" blockchain project
Third, if there is no Facebook, Twitter or telegraph group, it is likely to be a "fake" blockchain project
Fourth, if it is stated in the white paper or official website, it can be traded on XX trading platform in the future, Most likely, it's the "fake" blockchain project
v. the team members of the project side have low exposure, most likely it's the "fake" blockchain project
VI. there is no detailed project progress planning schele in the white paper, and most likely it's the "fake" blockchain project
the above 15 knowledge points are summarized by my own personal experience from 14 years to now. Now the blockchain investment instry is a mixture of good and bad. For the investment of a project, we need to be cautious. Any investment behavior is risky. How to control the risk, rece the risk in the minimum range, is the current investors should understand. We must make rational investment, not blindly follow the trend, and make investment judgment after a detailed understanding of the project
more shares can be paid attention to my personal official account, block chain Xiong Ke.
EOS is a public chain system at the bottom of blockchain developed by block. One, which is specially designed to support decentralized application of Commerce, and its code is open source
bitcoin is called blockchain 1.0 because it opens up the world of digital cryptocurrency and takes a decisive step from 0 to 1
Ethereum is known as blockchain 2.0, because it provides Turing complete virtual machine that can run smart contracts, bringing unlimited possibilities
and EOS is called blockchain 3.0, why? Two words: performance
The positioning of EOS is the slogan of its home page:English: the most powerful infrastructure for decentralized applications
Chinese: the most powerful decentralized application infrastructure
EOS expects to be an enhanced version of Ethereum, a high-throughput intelligent contract platform
although Ethereum has complete functions, it is limited by its design choice. Due to the block output speed of 15 seconds, the transaction throughput is far from large-scale practical level, which is only about 30 ~ 40tps (transaction / s). EOS, on the other hand, has chosen a different technology route, with the goal of achieving a considerable million TPS, which is quite attractive considering visa's actual processing speed of 1700tps
consensus mechanism of EOS
the reason why the throughput of bitcoin and Ethereum is so low is that they are constrained by the application scenario they envision and the consensus mechanism they choose for the scenario - both of them assume that the environment in which the system runs is totally untrustworthy, so they both adopt the consensus mechanism of proof of work
consensus, as the name suggests, is to reach a unified understanding of something - for blockchain, something refers to the confirmation of the transaction - any node to submit a transaction needs everyone's approval
the pow mechanism currently adopted by bitcoin and Ethereum is the design of the legendary Nakamoto Tsung. Under this mechanism, in order to obtain the bookkeeping right and digital currency reward, miners need to constantly dig for the compliant hash value, and confirm and package the transaction data through the consensus of hash value. POW has no access threshold, and any node has equal rights to participate in bookkeeping. Of course, the probability of winning is related to computing power:
the price of ram is based on Bancor algorithm, that is, it is regulated by market supply and demand: if the supply of ram exceeds the demand, more EOS certificates are needed to buy ram, At this time, more EOS certificates can be obtained by selling ram
memory is a consuming resource, which cannot be redeemed and can only be bought and sold. Take the issue of currency on EOS as an example. At present, the issue of currency requires 20m of memory. An EOS can buy 20KB. According to the current storage price, issuing a currency will consume 1000 EOS. This is the source of EOS memory consumption
Course Overview
this course is for friends who are interested in the development of EOS decentralized application. The course covers the core concepts of EOS DAPP development, the development and deployment of smart contracts, and how the front page interacts with EOS blockchain. Finally, a complete DAPP development based on react and EOS is completed
Chapter 1: enter the world of EOS
to understand the core concepts of EOS, such as positioning and characteristics, consensus mechanism, payment computing model, etc
Chapter 2: Hi EOS
understand the overall framework of EOS node software and the functions of node server, wallet server and command-line tools, learn how to configure and start EOS node server and wallet server, and preliminarily understand the use of command-line tools
Chapter 3: wallet, key and account
understand the three core concepts related to personal identity in EOS: wallet, key and account, and learn how to use command-line tools to create wallet, key and account
Chapter 4: development and interaction of smart contracts
understand the concept and function of smart contracts, learn how to write and compile EOS smart contracts, and learn how to deploy and interact with contracts using command-line tools
understand the persistence mechanism of state in EOS smart contract, and learn to use multi index table to save contract state
Chapter 5: issue your own tokens
learn the principle and implementation mechanism of issuing tokens on EOS, and master how to use command-line tools to issue, transfer and view the balance of tokens through practical operation
Chapter 6: use code to interact with smart contract
understand the principle of interaction between application and EOS blockchain, and learn to use JSON RPC interface and eosjs encapsulation library to access EOS blockchain
Chapter 7: DAPP development of practical notes
comprehensively use EOS knowledge, use react to complete a decentralized application of EOS notes, and learn the complete process from requirement analysis to code implementation
The above course address is as follows: EOS tutorial1. Server programming: in the past, if you used C or C + + to do those things, go is very suitable, such as processing logs, data packaging, virtual machine processing, file system and so on
2, distributed system, database agent, middleware: for example, etcd
3. Network programming: at present, this area is the most widely used, including web application, API Application, download application, and the built-in net / HTTP package of go basically realizes all the network functions we usually use
4. Development of cloud platform: at present, many foreign cloud platforms are developing with go, and the well-known seven cattle cloud, Huawei cloud and so on all have procts that are developed with go and open source
5. Blockchain: at present, there is a saying that technical practitioners regard go language as the development language of blockchain instry. If you learn the blockchain technology, you will find that many blockchain systems and applications are developed with go. For example, ehtereum is the most famous public chain at present, and fabric is the most famous alliance chain at present. Both of them have go language versions, and go ehtereum is the version officially recommended by Ethereum
Many projects in the later stage of
are implemented by go language. This process is simpler than other languages, which also leads to the emergence of a large number of go language native development projects< br />
Nowadays, in order to face the pressure of life, people are doing some network part-time jobs. For example, blockchain is a good network part-time job, and it is also relatively easy. Especially for college students, it is a very suitable network part-time job< so for those who don't understand blockchain, what aspects should they learn from? This can be developed according to its own situation. If you have the conditions, you can buy some information on the Internet to view the relevant content. You can also search for some relevant knowledge on the Internet to learn. Of course, you can also consult friends who understand it
in addition, the most important point is to understand the background knowledge and historical structure of blockchain, what is blockchain, and really understand its meaning. When successfully contacting the blockchain, don't be proud. Be open-minded to learn how other people do the blockchain, and have a persistent heart. In this way, you can quickly master the blockchain
Chinese Name: digital signature English Name: digital signature definition: data that exists in the data information in electronic form, or as its attachment or logically associated with it, can be used to identify the identity of the data signer and indicate the signer's recognition of the information contained in the data information. Applied discipline: Communication Science and Technology (first level discipline); The content above network security (secondary discipline) is approved and published by the national science and technology terminology Approval Committee
help edit network business card
digital signature process digital signature (also known as public key digital signature, electronic signature) is a kind of common physical signature written on paper, but it uses the technology in the field of public key encryption, A method for identifying digital information. A digital signature usually defines two complementary operations, one for signature and the other for verification<
directory
basic introction
main functions
signature process
Personal Secure E-mail certificate
identify virus with digital signature
cause analysis
usage method
principle feature authentication
integrity
non repudiation
basic introction of how to implement
java digital signature steps
main functions
signature process
Personal Secure E-mail Certificate
identify virus with digital signature
cause analysis
usage method
principle and feature authentication
integrity
non repudiation
how to implement Java digital signature steps to start editing this paragraph basic introction
Digital signature does not mean to scan your signature into a digital image, or use the touchpad to obtain the signature, let alone your signature. Digital signature is a digital string that can only be generated by the sender of information, which can not be forged by others. This digital string is also an effective proof of the authenticity of the information sent by the sender. Digital signature is the application of asymmetric key encryption technology and digital digest technology. The integrity of the digital signature file is very easy to verify (no need for the seal, the signature and the handwriting expert), and the digital signature is non repudiation (no need for the handwriting expert to verify). In short, the so-called digital signature is some data attached to the data unit, or the password transformation of the data unit. This kind of data or transformation allows the receiver of the data unit to confirm the source of the data unit and the integrity of the data unit, and protect the data from forgery. It is a method of signing electronic messages. A signed message can be transmitted in a communication network. Digital signature can be obtained based on both public key cryptosystem and private key cryptosystem. At present, digital signature is mainly based on public key cryptosystem. Including ordinary digital signature and special digital signature. Common digital signature algorithms include RSA, ElGamal, Fiat Shamir, Guillou quisquater, Schnorr, ong Schnorr Shamir digital signature algorithm, DES / DSA, elliptic curve digital signature algorithm and finite automata Digital signature algorithm. Special digital signature includes blind signature, proxy signature, group signature, undeniable signature, fair blind signature, threshold signature, signature with message recovery function and so on. Obviously, the application of digital signature involves legal issues. The federal government of the United States has developed its own digital signature standard (DSS) based on the discrete logarithm problem over finite fields. Digital signature is a typical application of asymmetric encryption algorithm. The application process of digital signature is that the sender of data source uses its own private key to encrypt the data checksums or other variables related to the data content to complete the legal "signature" of the data. The receiver of data uses the public key of the other party to interpret the received "digital signature", and uses the interpretation results to test the integrity of the data, To confirm the validity of the signature. Digital signature technology is an important technology to confirm the identity in the virtual environment of network system. It can completely replace the "autograph" in the real process, which is guaranteed technically and legally. In digital signature applications, the sender's public key can be easily obtained, but his private key needs to be strictly confidential
edit the main functions of this paragraph
ensure the integrity of information transmission, the identity authentication of the sender, and prevent the occurrence of repudiation in the transaction. Digital signature technology is to encrypt the abstract information with the sender's private key and send it to the receiver together with the original. The receiver can decrypt the encrypted digest only with the public key, and then generate a digest for the received text with hash function, which is compared with the decrypted digest. If it is the same, it means that the received information is complete and has not been modified in the transmission process. Otherwise, it means that the information has been modified, so the digital signature can verify the integrity of the information. Digital signature is a process of encryption, and digital signature verification is a process of decryption< When sending a message, the sender uses a hash function to generate a message digest from the message text, and then encrypts the digest with his own private key. The encrypted digest will be sent to the receiver as the digital signature of the message, The receiver first calculates the message digest from the received original message with the same hash function as the sender, and then decrypts the digital signature attached to the message with the sender's public key. If the two digests are the same, the receiver can confirm that the digital signature belongs to the sender. Digital signature has two functions: one is to confirm that the message is actually signed by the sender, because others can't fake the sender's signature. Second, digital signature can confirm the integrity of the message. Because the characteristic of digital signature is that it represents the characteristics of the file, if the file changes, the value of digital signature will also change. Different files will get different digital signatures. A digital signature involves a hash function, the sender's public key and the sender's private key This is the description of message authentication! Digital signature is not that complicated. Digital signature: the sender performs e operation on message x with its own key to generate an unreadable ciphertext ESK, and then transmits the ESX to the receiver. In order to verify the signature, the receiver performs D operation on the sender's key to restore the message
Edit this section of personal security e-mail certificate
personal security e-mail certificate with digital signature function is a kind of user certificate, which refers to the certificate that the unit user must have to use the certificate mechanism to ensure security when sending and receiving e-mail. Personal security e-mail certificate is a digital security certificate conforming to X.509 standard. Combining digital certificate and S / MIME technology, it encrypts and signs ordinary e-mail to ensure the security, confidentiality, identity confirmation and non repudiation of e-mail content. The personal secure e-mail certificate with digital signature function includes the e-mail address of the certificate holder, the public key of the certificate holder, the Ca and the signature of the certificate. The realization of personal security e-mail certificate function depends on whether the user's e-mail system supports the corresponding functions. At present, MS Outlook, Outlook Express, Foxmail and Ca secure e-mail systems all support corresponding functions. Using personal secure e-mail certificate can send and receive encrypted and digitally signed e-mail, ensure the confidentiality, integrity and non repudiation of e-mail transmission, and ensure the authenticity of the identity of all parties in e-mail communication< How to distinguish digital signature attacks? There are two ways: 1. To view the details of the digital signature, we should view the details of the digital signature and click the "details" button. We will find the difference between the normal exe and the infected (or bundled Trojan) exe digital signature. The details of the normal exe digital signature are tampered with, and the EXE digital signature information is invalid. Method 2, use the digital signature verification program sigcheck.exe (you can find this tool on the network, one of the components of the famous system toolkit sysinternal suite.) The result of digital signature exception is: C: &# 92; Documents and Settings\ litiejun\??&# 92; Modify.exe: verified: unsigned file date: 15:46 2008-5-23 Publisher: n / a description: n / a proct: n / a version: n / a file version: n / a normal result of digital signature is: C: &# 92; Documents and Settings\ litiejun\??&# 92; Che.exe: verified: signed signing date: 16:28 2008-4-29 Publisher: n / a description: n / a proct: n / a version: n / a file version: n / A, If you don't destroy the digital signature in exe, the digital signature may look normal after infection. But carefully look at the file properties or check the hash value of the file, you will find that the EXE program is not the most original version. 2. If the digital signature file of the software publisher is stolen, the attacker can also package the EXE program that is bundled with Trojan horse or infected with virus with digital signature, which is more serious in this case. If an enterprise applies for a digital signature certificate, it must keep it properly, otherwise it will have endless troubles
Edit how to use this paragraph
you can digitally sign every email you send. This does not mean signing. It is generally mistaken for signature. In mainland China, digital signature has legal effect and is widely used. In 2000, the new contract law of the people's Republic of China confirmed the legal effect of electronic contract and electronic signature for the first time. Since April 1, 2005, the first law of the people's Republic of China on electronic signature has been formally implemented< Each person has a pair of "keys" (digital identity), one of which is known only by herself (key), and the other is public (public key). Use the key when signing and the public key when verifying the signature. And because anyone can sign to claim that she / he is you, the public key must be registered with the person trusted by the recipient (identity authentication authority). After registration, the authentication authority will send you a digital certificate. After signing the document, you will send the digital certificate together with the document and signature to the recipient. The recipient will verify with the identity authentication authority whether the document is really signed with your key. In communication, digital signature is generally used for the following reasons:
authentication
public key encryption system allows anyone to use the public key to encrypt when sending information, and digital signature enables the information receiver to confirm the identity of the sender. Of course, it is impossible for the receiver to be 100% sure of the sender's true identity, but only if the cryptosystem has not been deciphered. The importance of authentication is particularly prominent in financial data. For example, suppose a bank transmits instructions from its branches to its central management system. The format of the instructions is (a, b), where a is the account number of the account and B is the existing amount of the account. At this time, a remote client can first deposit 100 yuan, observe the transmission results, and then send instructions in the format of (a, b) one after another. This method is called
under the normal XP operating system, there are five to six svchost.exe processes, including three svchost.exe under the system user name, two svchost.exe under the network service user name, and one svchost.exe under the local service user name. The same is true for other systems. Their user names are system, network service and local service. If they are not, they may be viruses. And there is also a very important point is that the normal svchost.exe program is in Windows & # 92; System 32. If there is svchost.exe in other directory, it must be a virus. The number of svchost.exe in the process is not important. It depends on the user name and whether the location is in Windows & # 92; System 32. For example: Trojans like to be installed in C: &; windows\ Directory, because it is very confusing Oh, in fact, it is a Trojan horse, kill it< In general, this virus has the following situations:
1. It is the file of svchost.exe directly but placed in other directory. The clear method directly looks up the svchost.exe file. windows\ Except in system32 directory, all svchost.exe in other directories will be deleted< 2. Svchost.exe turns o into 0. Svch0st.exe. This is the well-known online banking theft virus. Some viruses don't have to add a letter to it or add a letter to it. For example, svchaost.exe. To confuse computer users. The virus is not powerful. Generally, it is to steal the user's keyboard input information and send the information to the designated mailbox. This kind of virus each big popular antivirus software can solve very well. As long as the antivirus software virus library update to the latest, you can completely solve this virus< 3. The CPU utilization rate of svchost.exe process is 100%. When this happens, it's not svchost.exe itself. It is caused by a process of the system using this process a lot. For example, a mole uses a lot of network resources. For example, the automatic update program of antivirus software. This is suitable for you to end the application one by one, and then check whether the CPU utilization rate of svchost.exe is not 100% to determine which program is wrong. If there is still no solution, you can go to the Microsoft website to update this program!