How does bitcoin accountant confirm time

1. In order to understand the technical principle of bitcoin, we need to understand two important cryptographic techniques: hash code: it converts a long string into a fixed length string, and its conversion is irreversible, that is, it is impossible to guess the original string from hash code. Sha256 is mainly used in bitcoin protocol
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

2. Bitcoin receives payments almost instantaneously. However, there is an average delay of 10 minutes before the network starts adding your transaction to a block to confirm the transaction and that you can use the received bitcoin. Confirmation means that there is a consensus on the Internet that the bitcoin you receive is not used to pay others, so it is recognized as your property. Once your transaction is included in one block, all subsequent blocks will include it, which will greatly consolidate this consensus and rece the risk of transaction cancellation. Each user can determine the time when the transaction is confirmed, but generally speaking, receiving six confirmations is as safe as waiting six months after a credit card transaction
anyone can become a bitcoin miner by running software on specialized hardware. Mining software monitors transaction broadcast through P2P network and performs appropriate tasks to process and confirm these transactions. Bitcoin miners can earn transaction fees paid by users to speed up transaction processing and additional bitcoin issued according to fixed formula

new transactions need to be included in a block with mathematical workload proof before they can be confirmed. This kind of proof is hard to generate because it can only be generated by trying billions of calculations per second. Miners need to run these calculations before their blocks are accepted and rewarded. As more people start mining, the difficulty of finding effective blocks will be automatically increased by the network to ensure that the average time to find a block remains at 10 minutes. Therefore, the competition for mining is very fierce, and no indivial miner can control the content contained in the block chain
workload proof is also designed to rely on previous blocks, which forces the time sequence of block chain. This design makes it extremely difficult to cancel previous transactions, because the workload proof of all subsequent blocks needs to be recalculated. When two blocks are found at the same time, the miner will process the first block received, and once the next block is found, it will be transferred to the longest block chain. This ensures that the mining process maintains a global consistency based on processing capacity
bitcoin miners can neither increase their rewards by cheating, nor deal with the fraulent transactions that destroy the bitcoin network, because all bitcoin nodes will reject the blocks containing invalid data that violate the bitcoin protocol rules. Therefore, even if not all bitcoin miners can be trusted, the bitcoin network is still secure
if you still don't understand, go to bitcoin home to see the deeper understanding of netizens.

3. It seems to take half an hour to an hour. Generally, one confirmation is enough, but some platforms need three to five confirmations.

4. If you want to ensure the irreversibility of the transaction, you have to wait for six data blocks to be fully confirmed, which takes at least one hour to confirm.

5. Generally, only the payee can return bitcoin after 24 hours. Any bitcoin transaction is irreversible and can only be returned by the payee.

6.

Transaction mode of bitcoin

bitcoin is e-cash similar to e-mail, and both parties need "bitcoin wallet" similar to e-mail and "bitcoin address" similar to e-mail address. Just like sending and receiving e-mail, the remitter pays bitcoin directly to the other party through a computer or smart phone according to the recipient's address. The following table lists some websites that download bitcoin wallets and addresses for free

a bitcoin address is a string of about 33 characters long, consisting of letters and numbers, always starting with 1 or 3, such as & quot& quot; Bitcoin software can generate address automatically, and it doesn't need to exchange information online, so it can be offline. More than 2 bitcoin addresses are available. Figuratively speaking, there are about two grains of sand in the world. If there is an earth in each grain of sand, then the total number of bitcoin addresses far exceeds the number of all the sand on all these "earths"

the bitcoin address and private key appear in pairs, and their relationship is just like the bank card number and password. A bitcoin address is like a bank card number, which records how much bitcoin you have on it. You can generate bitcoin address at will to store bitcoin. When each bitcoin address is generated, a corresponding private key of the address will be generated. This private key proves that you have ownership of the bitcoin at that address. We can simply understand the bitcoin address as the bank card number, and the private key of the address as the password of the corresponding bank card number. Only when you know the bank password can you use the money on the bank card number. Therefore, please keep your address and private key when using bitcoin wallet

after the transaction data of bitcoin is packaged into a "data block" or "block", the transaction is initially confirmed. When a block is linked to a previous block, the transaction is further confirmed. After six block confirmations in a row, the transaction was irreversibly confirmed. Bitcoin P2P stores all transaction history in a "blockchain.". The blockchain continues to extend, and once new blocks are added to the blockchain, they will not be removed. Blockchain is actually a distributed database composed of a group of scattered client nodes and all participants, which is a record of all bitcoin transaction history. Nakamoto predicts that when the amount of data increases, users hope that not all the data will be stored in their own nodes. In order to achieve this goal, he uses the hash function mechanism. In this way, the client will be able to automatically eliminate those parts that it will never use, such as some very early bitcoin transactions

7. Hello:
your question is: 1. If you receive cash for goods sales, you will recognize the revenue after receiving cash. If it is a transfer or telegraphic transfer, it will take several days to arrive at the account, then the revenue will be recognized after the goods are delivered. 2. It should be said that the invoice is issued when the revenue is recognized. The time of issuing invoice should be consistent with the time of confirming revenue in theory. Billing is to obtain the evidence of asking for sales money, which means the realization of sales, so billing should be based on the time of revenue recognition. Article 33 of the measures for the administration of invoices stipulates that "the units and indivials that fill in and issue invoices must issue invoices when business operations occur and business income is recognized.". But in the actual work, the income can be recognized when the invoice is issued in the next month
in accounting, the specific time for determining revenue is as follows:
the day when revenue is recognized is the day when the payment is received or the sales payment voucher is obtained. According to the different sales settlement methods, it can be divided into:
1. The day when the goods are sold by direct collection is the day when the sales payment is received or the sales payment voucher is obtained, regardless of whether the goods are delivered or not
2. The day when the goods are sent out and the collection proceres are completed is the day when the goods are sold by means of collection commitment and entrusted bank collection
3. If goods are sold on credit or by installments, it is the date of receipt agreed in the written contract (whether received or not, it is confirmed on the same day). If there is no written contract or there is no date of receipt agreed in the written contract, it is the date of delivery of goods
4. The goods are sold by the way of payment in advance, which is the day of delivery
5. Consign other units to sell goods on a commission basis, which is the day when the consignment list of the unit is received or all or part of the goods are received. In order to receive the consignment list and payment for goods, it shall be the day 180 days after the consignment goods are sent out.

8. The basic accounting assumption is the premise of enterprise accounting confirmation, measurement and report, and is the reasonable setting of the time and space environment of accounting. The basic accounting assumptions include accounting entity, going concern, accounting period and monetary measurement. The basic premise of clear accounting is to make the accounting practice in some uncertain factors can be carried out normally

9.

Revenue is recognized when the buyer "confirms receipt"

the specific operation is to establish a virtual customer on the system, which is called & quot; Flagship store;, Then the monthly delivery orders are summarized according to the items. At the end of the month, a delivery order is made to confirm the revenue (the freight should also be recognized in the revenue). The cost is the cost of the items on the delivery order, and the corresponding carry forward is good. The return received in the current month will offset the income of the current month

after the revenue is recognized on the system, the & quot; Flagship Store & quot; The customer's accounts receivable, and then export the monthly bills of Alipay monthly, after the collation and sorting, the actual receipts will be collected receivables. p>

"in some cases, when enterprises sell procts or provide services, they will award customers bonus points, such as the mileage accumulated by airlines. After customers meet certain conditions, they will exchange bonus points for free or discounted goods or services provided by enterprises or third parties

the Seller shall allocate the payment for goods or receivables from the sales between the income generated from the sales of goods or services and the fair value of the reward points, recognize the part of the payment for goods or receivables less the fair value of the reward points as income, and recognize the fair value of the reward points as deferred income. The fair value of bonus points is the amount that can be obtained by indivial sales

the fair value of reward points can not be observed directly, and the awarding enterprise can estimate the fair value of reward points by referring to the fair value of the exchanged reward or other valuation techniques. Under the following circumstances, granting the enterprise may rece the fair value of bonus points:

provide the fair value of bonus points to customers who have not obtained bonus points from the initial sales; The part of bonus points that is not expected to be redeemed by customers. "

< H2 > expand data

set up a virtual customer on the system, which is called "flagship store", and then summarize the monthly delivery orders according to the items, and make a delivery note at the end of the month to confirm the revenue (freight should also be confirmed in the revenue), and the cost is the cost of the items on the delivery note, which should be carried forward accordingly. The return received in the current month will offset the income of the current month

in addition, people who buy things on tmall seldom need to issue invoices, but our company does not issue invoices when filing tax returns

recognizes revenue on the system, it forms the accounts receivable of the "flagship store" customer, then exports Alipay monthly bills every month, collation and collation, and the actual receipts are collected to collect receivables. p>