Open source blockchain project Git
after entering the research of Ethereum, I wanted to start from the underlying source code at the beginning, but the whole process was rather difficult. After re analyzing our requirements, I felt that we could develop to some extent and meet some needs by using its existing interface, so I translated the comments of the source code, basically understood the role of each mole, and no further modification was needed, After all, Ethereum is also a project that took dozens of big bulls a long time to build.
it is very difficult for us to successfully transform it into what we want in a period of time. The faster, the easier, the better
and there is a very important problem. If Ethereum is changed, it will not be able to connect to its public network and use the second largest amount of computing power in the world. This is a matter of putting the cart before the horse. It seems that the answer is wrong, but the main expression is that if the subject wants to do development, it is enough to carefully analyze a project,
after all, the logic is almost the same. We should learn more about blockchain and pay attention to ATV
Blockchain is the general trend of the tuyere project, but when choosing blockchain projects, we must shine our eyes and find a team with technology, application and real down-to-earth work. Otherwise, it may come to nothing, because since it is a trend, naturally there are a lot of speculation and fraud projects
here, we mainly introce utispace, the first blockchain distributed storage project with perfect technology and real application in the world
investment highlights
a brief introction to utispace: is 5g coming? Have big data, artificial intelligence, wearable devices, Internet of things and AI entered our lives? Is the phone running out of memory
stuck
the high-speed information flow inevitably needs infinite storage space, but the current storage space is never enough
for example, the storage space of 4G mobile phone determines the price of mobile phone, but what about 5g mobile phone? More to 10 times the demand for 4G space storage, the price will be expensive
where there is demand, there is market. In the past, we need to build a big data storage base station for big data storage. The cost is very high. It costs 10 billion yuan at any time, and the security is very low (the base station will be hot and prone to fire and earthquake, what should we do? If hackers attack all data, they will be paralyzed). In addition, no matter how big the base station is, its storage capacity is limited, and it can never meet the demand of doubling the amount of data generated by the market, resulting in a large number of useful data homeless. At present, 67% of the data has been deleted, which is a great loss
so who can solve the data storage with large storage, high security, low cost and low energy consumption
today, the decentralized distributed storage space of China's own brand utispace, together with the digital pulse chain Laboratory of Zhejiang University, has solved this worldwide problem. Thus, it takes the lead in occupying the big cake of distributed data storage
you'll know when you go there, and go out from exit a / B to Huaxia Art Center Square.
Now, almost all of them cut off leeks one after another, saying that there is another new leek growing into...
the concept of blockchain is too new. A wave of smart people can easily use this concept to create some so-called creative gimmicks. In fact, it is essentially grafting the name of new concept to do something illegal without any egg
generally speaking, all the blockchain instries that are not combined with entities are hooligans
when it comes to on-the-spot projects, such as court power confirmation, agricultural proct traceability, electronic invoice, etc., have been implemented, but these are all about people's livelihood. There are also some project parties, such as tuken Mall (distributed scene e-commerce, online in May), gongxinbao (personal data right confirmation), Hashi future, etc., which are good on-the-spot projects, You can go to their official website or official account.
if you are looking for an investment, you have to take it easy. If you don't understand it, don't make a blind investment. If you understand it within the scope of your balance, you can make another investment... Remember
you can observe the projects mentioned just now, as long as the implementation can promote the real economy, I hope it can help you
distributed
git ensures that each code warehouse maintains a complete project library locally, not just the branch in which it works and its own submission history. At the same time, it also keeps all the snapshot and index information after the latest pull
on the blockchain, each node keeps a complete database locally, not just its own transaction information
traceability
in Git commit chain, each commit object contains a parent object (the object of the last commit, except the first commit), which can trace all the previous records
on the blockchain, each block contains the index of the previous block (except the genesis block), which can trace all valid transactions before<
tamper proof
in Git's commit chain, each object itself calculates a checksum before storing, and then references it with a checksum. Once modified, the checksums will not be correct, which means that it is impossible to change the contents of any file or directory without git's knowledge< The mechanism used by git to calculate the checksums is called SHA-1 hash. This is a string composed of 40 hexadecimal characters (0-9 and A-F), which is calculated based on the content or directory structure of the file in GIT. SHA-1 hash looks like this:
in the blockchain, each block contains the last block ID, and this block ID has two SHA-256 hashes, which are calculated based on the block content. Once the content is modified, the hash will change, which is inconsistent with the chain of other nodes and cannot be added to the longest chain, so the content cannot be tampered with< 2. Difference
collective consensus and central node will: 1 - blockchain merges based on collective consensus (POW / POS) to form the longest chain, which is the main chain
2 - in Git system, when multi node cooperation is carried out through the warehouse hosting platform, it is the manager of the platform project who controls the power of merge, which reflects the will of the central node<
cryptography
1 - in bitcoin blockchain, cryptography mainly uses the following methods
in the whole system of bitcoin blockchain, a large number of public encryption algorithms are used, such as Merkle tree hash number algorithm, elliptic curve algorithm, hash algorithm, symmetric encryption algorithm and some coding algorithms. The functions of various algorithms in bitcoin blockchain are as follows:
A) hash algorithm
the two hash functions used in bitcoin system are: 1. SHA-256, which is mainly used to complete pow (proof of workload) calculation; 2. Ripemd160, mainly used to generate bitcoin address
b) Merkle hash tree
binary tree or multi tree based on hash value. In the computer field, Merkle tree is mostly used for integrity verification. In the distributed environment, integrity verification can greatly rece the complexity of data transmission and calculation<
C) elliptic curve algorithm
in bitcoin, the public key cryptography algorithm based on secp256k1 elliptic curve mathematics is used for signature and verification. On the one hand, it can ensure that the user's account is not replaced by an impostor, on the other hand, it can ensure that the user can not deny the signed transaction. The private key is used to sign the transaction information, and the user's public key is used to verify the signature. If the verification is passed, the transaction information will be recorded and the transaction will be completed
d) symmetric encryption algorithm
the official bitcoin client uses AES (symmetric block cipher algorithm) to encrypt the wallet file. After the user sets the password, the private key of the wallet is encrypted by the user set password through AES to ensure the security of the private key of the client
e) base58 encoding
base58 is a unique encoding method used in bitcoin. It is mainly used to generate the wallet address of bitcoin, which is similar to the permutation algorithm mechanism in classical cryptography. Its purpose is to increase the readability of bitcoin and change the binary hash value into the address we see
2 - git: SSH key is mainly used for remote login verification, SHA-1 is used for code content checking sum<
SSH is the abbreviation of secure shell, developed by IETF's network working group. It is a protocol designed to provide security for remote login sessions and other network services. SSH protocol can effectively prevent information leakage in the process of remote management< The process of SSH transmission is as follows: (1) the remote host receives the user's login request and sends its public key to the user 2) The user uses the public key to encrypt the login password and send it back 3) The remote host uses its own private key to decrypt the login password. If the password is correct, the user is allowed to log in.