Bitcoin forgery timestamp
The concept of bitcoin was first proposed by Nakamoto on November 1, 2008, and was officially born on January 3, 2009. According to the idea of Nakamoto, the open source software is designed and released, and the P2P network on it is constructed. Bitcoin is a virtual encrypted digital currency in the form of P2P. Point to point transmission means a decentralized payment system
bitcoin network generates new bitcoin through "mining". In essence, the so-called "mining" is to use computers to solve a complex mathematical problem to ensure the consistency of bitcoin network distributed accounting system. Bitcoin network will automatically adjust the difficulty of mathematical problems, so that the whole network will get a qualified answer about every 10 minutes. Then bitcoin network will generate a certain amount of bitcoin as block reward to reward the person who gets the answer
unlike all currencies, bitcoin does not rely on a specific currency institution to issue. It is generated by a large number of calculations based on a specific algorithm. Bitcoin economy uses a distributed database composed of many nodes in the whole P2P network to confirm and record all transactions, and uses cryptography design to ensure the security of all aspects of currency circulation. The decentralized nature and algorithm of P2P can ensure that it is impossible to artificially manipulate the value of bitcoin through mass proction. The design based on cryptography can make bitcoin only be transferred or paid by the real owner. This also ensures the anonymity of money ownership and circulation transactions. The biggest difference between bitcoin and other virtual currencies is that the total amount of bitcoin is very limited and it has a strong scarcity.
public key system: corresponds to a public key and a private key, keeps the private key in the application and publishes the public key. When Party A transmits information to Party B, it can use Party A's private key to encrypt the information, and Party B can use Party A's public key to decrypt the information, so as to ensure that the third party cannot impersonate Party A to send the information; At the same time, when Party A transmits information to Party B, it is encrypted with Party B's public key and sent to Party B, and then Party B decrypts it with his own private key, so as to ensure that the third party cannot eavesdrop on the communication between the two people. RSA is the most common public key system, but the lliptic curve digital signature algorithm is used in bitcoin protocol. What's the difference between cash and bank account? Bitcoin is an electronic currency in BTC. In this article, it is also used to refer to the whole bitcoin system. Like opening an account in a bank, the corresponding concept in bitcoin is address. Everyone can have one or more bitcoin addresses, which are used to pay and collect money. Each address is a string that starts with 1. For example, I have two bitcoin accounts, and. A bitcoin account is uniquely determined by a pair of public key and private key. To save the account, you only need to save the private key file. Unlike bank accounts, banks keep all transaction records and maintain the book balance of each account, while bitcoin's transaction records are jointly maintained by the whole P2P network through a pre agreed protocol. How much money is in my account address? Although the current account balance can be seen by bitcoin software, unlike banks, there is no place to maintain the book balance of each address. It can only calculate the account balance in real time through all historical transactions. How do I pay? When I pay from address a to address B of the other party, the payment amount is e. at this time, both parties will announce the transaction information to each network node, telling address a to pay to address B, and the payment amount is e. In order to prevent the third party from forging the transaction information, the transaction information will be encrypted with the private key of address A. at this time, the network node receiving the transaction information can use the public key of address a to verify that the transaction information is indeed sent by address a. Of course, trading software will help us do these things, we just need to input the relevant parameters in the software. What will the network node do after receiving the transaction information? This is the most important part of the bitcoin system, which needs to be elaborated. For the sake of simplicity, only bitcoin protocol has been implemented. In the current version, each network node will save all transaction information synchronously. There are two kinds of transaction information in history, one is & quot; Verified & quot; The transaction information, that is, the verified transaction information, is stored in a series of "blocks". Each & quot; block" Is the previous & quot; bock" The ID of each block is the hash code of the hash code of the block and the new transaction information (see an actual block). The other category refers to those who also & quot; Unverified & quot; The transaction information just paid above belongs to this category. When a network node receives new unverified transaction information (possibly more than one), it can calculate the book balance of each address at that time because the node keeps all the transaction information in history, so it can calculate whether the transaction information is valid, that is, whether there is enough balance in the payment account. After eliminating the invalid transaction information, it first takes out the last & quot; block" Then, the unverified transaction information is combined with the ID, and a verification code is added to form a new "block". It needs a lot of calculation to build a new block, because it needs to calculate the verification code, so that the above combination becomes a block, that is, the first several bits of the hash code of the block are 1. At present, the first 13 bits need to be 1 (generally, the specific method is uncertain), which means that if the block is generated by enumeration method, the average number of enumerations is 16 ^ 13. Using CPU resources to generate a block is called "gold mining", because the proction of the block will get a certain reward, and the reward information has been included in the block. When a network node generates a new block, it will broadcast to other network nodes. However, this network block may not be accepted by the network, because it is possible that other network nodes have proced the block earlier. Only the earliest block or the block with the largest number of subsequent blocks is valid, and the remaining blocks are no longer used as the initial blocks of the next block. How does the other party confirm that the payment is successful? When the payment information is distributed to the network node, the network node begins to calculate whether the transaction is valid (that is, whether the account balance is enough to pay), and attempts to generate blocks containing the transaction information. When six blocks (one direct block and five subsequent blocks) contain the transaction information, the transaction information is considered "verified", so that the transaction is formally confirmed, and the other party can confirm the successful payment. A possible problem is that I will pay the balance of address a to address B, and at the same time pay to address C. If I only verify that the single comparison transaction is valid. At this point, my way of cheating is to generate six blocks including B to B and six blocks including C to C before the truth is revealed. Because I need a very long CPU time to generate a block, compared with the whole network, the probability of my cheating success is very small. What is the motivation of network nodes to proce blocks? As can be seen from the above description, in order to make the transaction information effective, the network node needs to generate 1 and 5 subsequent blocks to contain the transaction information, and such block generation is very CPU intensive. How to let other network nodes help to proce blocks as soon as possible? The answer is very simple. The agreement stipulates that BTC will be rewarded for the address where the block is proced, as well as the Commission promised by both parties. At present, the reward for procing a block is 50btc, which will be halved every four years in the future. For example, the reward will be 25btc from 2013 to 2016. Is the transaction anonymous? Yes, and No. All bitcoin transactions are visible. We can check all transaction records of each account, such as mine. But what's different from the banking monetary system is that everyone's account itself is anonymous, and everyone can open many accounts. In general, anonymity is not as good as it claims. But bitcoin has another advantage in doing black market trading: it can't be frozen. Even if the police trace a bitcoin address, there is nothing they can do unless they trace the computer used by the exchange based on the Internet address. How to ensure that bitcoin does not depreciate? Generally speaking, in the case of equivalent trading activities, the value of money is inversely proportional to the amount of money issued. Unlike the traditional money market, the central bank can determine the amount of money issued. Bitcoin does not have a central issuing institution. Only by procing blocks can we get a certain amount of BTC currency. Therefore, bitcoin's new amount of money depends on: 1. The speed of procing blocks: bitcoin's agreement stipulates that the difficulty of procing blocks is fixed at an average of 2016 every two weeks, about 10 minutes. Moore's law of doubling CPU speed every 18 months will not speed up the proction of block. 2. The number of rewards for block proction: at present, 50 BTC is awarded for each block proced, which is halved every four years. In 2013, 25 BTC is awarded, and in 2017, 12.5 BTC is awarded. Considering the above two factors, bitcoin's currency issuing speed is not controlled by any single node in the network. Its protocol makes the currency stock known in advance, and the maximum stock is only 21 million BTC
for the time stamp in the blockchain, jinwowo group understands it like this:
the time stamp is written directly in the blockchain, and the generated blocks in the blockchain can not be tampered, because once tampered, the generated hash value will change and become an invalid data
each time stamp will also include the previous time stamp into its random hash value. This process is repeated and connected in turn, and finally a complete chain will be generated.
is called ABIS port
BTS and MS
is called um port, that is, air interface
there are actually two interfaces between BSC and MSC, because there is also a TC mole, and the two interfaces are ater port and a port respectively.
the new BSC is basically optical port BSC. Go directly to SDH or PTN equipment on the transmission side, go to the base station side through the transmission network, and convert it into 2m electrical signal to the base station (BTS). Some base station equipment support the optical port, and may be directly inserted into the optical fiber.
bitcoin is a virtual currency and has no issuing institution
Unlike most currencies, bitcoin does not rely on specific currency institutions to issue. It is generated by a large number of calculations based on specific algorithms. Bitcoin economy uses a distributed database composed of many nodes in the whole P2P network to confirm and record all transactions, and uses cryptography design to ensure the security of all aspects of currency circulation. The decentralized nature and algorithm of P2P can ensure that it is impossible to artificially manipulate the value of bitcoin through mass proction. The design based on cryptography can make bitcoin only be transferred or paid by the real owner. This also ensures the anonymity of money ownership and circulation transactions. The biggest difference between bitcoin and other virtual currencies is that the total amount of bitcoin is very limited and it has a strong scarcity. The monetary system used to have no more than 10.5 million in four years, after which the total number will be permanently limited to 21 millionbitcoin can be cashed and converted into the currency of most countries. Users can use bitcoin to buy some virtual items, such as clothes, hats and equipment in online games. As long as someone accepts it, they can also use bitcoin to buy real-life items
Terminology in the field of information technology. In essence, it is a shared database. The data or information stored in it is characterized by "unforgeability", "trace in the whole process", "traceability", "openness and transparency" and "collective maintenance". Based on these characteristics, blockchain technology has laid a solid "trust" foundation, created a reliable "cooperation" mechanism, and has broad application prospects
blockchain originated from bitcoin. On November 1, 2008, a person who called himself Zhongben Cong published the article "bitcoin: a peer-to-peer e-cash system", which describes the framework concept of e-cash system based on P2P network technology, encryption technology, timestamp technology, blockchain technology, etc., which marks the birth of bitcoin
in recent years, the world's attitude towards bitcoin has gone up and down, but as one of the underlying technologies of bitcoin, blockchain technology has been paid more and more attention. In the process of bitcoin formation, blocks are storage units that record all the communication information of each block node in a certain period of time
each block is linked by random hash (also known as hash algorithm), and the latter block contains the hash value of the former block. With the expansion of information exchange, one block is connected with another block one after another, and the result is called blockchain
extended materials:
from the perspective of science and technology, blockchain involves many scientific and technological issues such as mathematics, cryptography, Internet and computer programming. From the perspective of application, in short, blockchain is a distributed shared ledger and database, which is decentralized, tamper proof, traceable, collective maintenance, open and transparent
blockchain is a new application mode of distributed data storage, point-to-point transmission, consensus mechanism, encryption algorithm and other computer technologies. Blockchain is an important concept of bitcoin, which is essentially a decentralized database, as well as the underlying technology of bitcoin
in fact, the word blockchain does not appear in the original English version of bitcoin white paper, but the word chain of blocks. In the earliest Chinese translation of bitcoin white paper, chain of blocks was translated into blockchain. This is the earliest time when the Chinese word "blockchain" appeared