Mexico BTC paper
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
There are several reasons as follows:
1. Foxconn was blackmailed by hackers for 1804 bitcoins. Foxconn's response is not a big problem< p> According to media reports, Foxconn was attacked by hackers who asked for 1804 bitcoins. For a while, everyone wanted to know what Foxconn would do, so Foxconn said, "it's not a big problem, it's being dealt with " 
in a word, according to the above analysis, the advantage of bitcoin to hackers is that they only need bitcoin< otherwise, if you take other money, you will have to spend your life
indivial visa application process for Mexico:
the first step is to prepare visa information: download the visa application form and invitation letter from the official website of the Mexican Embassy. Please fix the template
the second step is to collect the visa after the applicant has prepared the information and submitted it to the embassy for fingerprint interview
the information required for personal travel in Mexico is as follows:
< UL >Passport: the passport is valid for more than 6 months, and there are at least 2 blank pages. I need to sign my name at the signature office. If you have an old passport, please provide it together
Photos: 2 white background color photos taken in recent half a year, the front is bareheaded and without glasses, the size is 3.9cm x 3.1cm
ID card: please provide a clear of the second generation ID card, with the front and back sides on the same page
account book: please provide a of each page of all members in your account book; If it is a collective account, provide the home page and my page
materials of Chinese company:
certificate of employment: Please print it on the company's letterhead in English, including the following information:
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address, telephone and fax number of the company
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applicant's name, position, income and working years
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the purpose of the trip, the exact time of the leave, who is responsible for the travel expenses, and the unit reserves the position for the applicant
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spelling (printing), signature, position (printing), company name (printing) and official seal of the company representative's name in pinyin, and the signer can not be the same person or the applicant himself
< / OL >
unit qualification certificate: of business license or organization code certificate of the unit, with the latest annual inspection and official seal
Personal asset certificate current fund certificate: the original and of bank statement, with an average monthly balance of about RMB 10040 in the past six months. Auxiliary assets: it is recommended to provide a of my real estate certificate, a of my driving license (vehicle information page and photo page), stock securities and other asset materials. The more sufficient the assets, the higher the success rate of visa. Travel planning materials itinerary: please tell us the detailed itinerary, including: departure time (mm / DD / yyyy), departure time (mm / DD / yyyy), plan to visit the city and related scenic spots English)the process of handling mexican visa through travel agency (take CYTS as an example):
the first step is to browse the website of travel agency to understand the information needed for handling, and contact customer service to inquire about handling questions
the second step is to photograph the baby and pay for it, and ask the customer service for the information package needed for the mexican visa
the third step is to deliver the information to the travel agency. After receiving all the information, the travel agency will return the information to the guest for fingerprint interview after preliminary examination.
the fourth step is to send it back to the guest the next day after signing out
There is a bus to Hangzhou at Huangshan passenger terminal. The screenshot is as follows:
in French currency, the BTC trading value in the same week reached 9.2 million dirhams (about US $182000), ranking third in the weekly trading activities of the Dominican market in history, and the highest trading volume in the week since January 13, 2018
in the week since December 22, the weekly P2P transaction volume in Mexico also reached the peak, reaching 9.34 million Mexican pesos (about $488000) or 115 BTC, ranking second in the transaction record in terms of Mexican pesos.
from May 18, 2016, Chinese citizens holding valid entry visa from the United States, the United Kingdom, Canada, Japan, Ireland or Schengen countries, and holding APEC Business Travel Card (ABTC) marked with Mexico who enter Mexico for a short time and stay for non labor visit can go directly to Mexico.
Yes. If it is a non labor visit to Mexico, and stay less than 180 days, holding a Japanese visa can be visa free entry to Mexico
According to the Mexican Embassy in China, foreigners who visit Mexico without labor service and stay for less than 180 days (for example, tourism, business, study abroad or engaged in non labor technology and scientific research work) do not need to apply for a visa:1. Those who hold valid visa from any of the following countries enter Mexico for multiple times and are not transit visa. The United States, Japan, Great Britain and Northern Ireland or any Schengen country
2. Holders of permanent residence permit from any of the following countries. Canada, the United States, Japan, Great Britain and Northern Ireland or any Schengen country, Colombia, Chile or Peru
extended information:
attend visa interview in Mexico and submit the following materials:
A) visa application form of Consulate
in the case of young children or minors or persons subject to judicial guardianship under the provisions of the civil law, the visa application form of the consulate must be signed by both parents or by the performing guardian, and the consular officer or commissioner is present
if one of the parents is unable to go to the consulate to apply for a visa for his or her minor child, he or she must present a power of attorney from the other parent, stating that he or she agrees to apply for a visa for Mexico
if the parents of the child or minor applicant exercise the right by the court judgment, only one of the parents should proce the notarial certificate of the legal judgment
if the young child or minor applicant goes to the consulate alone or is accompanied by a third-party alt, he / she needs to proce a certificate notarized by the notary office or the relevant department with notarization qualification to prove that his / her parents or the person exercising the ty of parental guardianship allow him / her to apply for a mexican visa and agree to grant him / her a visa
b) provide Mexican immigration authorities with the information required in the visa interview, such as personal identity data, purpose of the visit, and relevant information required according to the type of visa applied
ring the visa interview, the consulate will review the information and materials provided by the applicant. If the information and materials are approved, the visa fee will be charged first, and the visa will be issued within 10 working days from the date of the visa interview
C) provide the original or notarized of the materials to be prepared according to the type of visa application (for details, please click the corresponding proceres column)
References: important notice of visa office of Mexican Embassy in China - Mexican Consulate General in Shanghai