Bitcoin: A point-to-point electronic cash system Essentials refinement

Introduction

The blockchain is essentially a decentralized, distributed ledger database, which itself is a series of data blocks generated by the use of cryptography, and each data block contains information that is validated by multiple Bitcoin network transactions.

Simple Introduction to Blockchain technology

Today's transactions on the Internet are all based on trusted third-party institutions to process electronic payment information. This system is constrained by the weakness of the "credit-based model", where people cannot achieve completely irreversible transactions. and the presence of financial intermediaries increases the cost of transactions and limits the size of a viable minimum transaction. In this transaction, both parties are required to have trust, and the merchant will ask the customer for completely unwanted personal information, while a certain percentage of fraudulent customers are unavoidable.

In order to solve these problems, we need a new electronic payment system, which is based on the principle of cryptography and not based on credit, so that any agreement between the two parties can be paid directly, thus eliminating the need for third-party intermediaries to participate. Eliminate the possibility of rolling back (reverse) payment transactions, which can protect specific sellers from fraud, and for those who want to protect buyers, the establishment of a common third-party guarantee mechanism in this environment is also easy to add pleasure.

in this paper, a peer-to-peer distributed Timestamp server is presented to generate the electronic transaction proof which is arranged and recorded according to the time, thus solving the double payment problem. The system is safe as long as the sum of the computational power controlled by the honest node is greater than the sum of the computational power of the Cooperative (cooperating) attacker. Issues that may occur with trading bitcoins

Double Payment:

If the same amount of money (digital currency) is repeated two times, it is a double payment issue.

How to Solve:

all the transactions are open : The entire network of historical transactions Open, then the number of bitcoins in each account is not represented by a data, but based on historical transactions. And this historical trading chain is recognized by the whole network, can guarantee not to be false.

need to have a timestamp, all trades are in order : All trades, to be in order, to add time stamp, before a successful transaction, the entire trading chain is recognized, the next transaction is based on the previous transaction to generate, the entire transaction is a chain of trade, so as to ensure that the double payment is not. need to invest in computing resources to confirm the transaction : the confirmation of the transaction, need to input the calculation resources to confirm, Bitcoin introduced the workload proof, the miners put the calculation force to package the transaction, if the need to modify a block of transactions, need to re-calculate all blocks since the block, refer to the current calculation of the Bitcoin network, This is almost impossible in mathematics. Time Stamp Server

This solution first presents a "timestamp server". The timestamp server enforces a random hash of a set of data that exists as a block (block) and broadcasts the random hash as if it were posted on a news or World News Group Network (Usenet) 2345. Obviously, the timestamp confirms that the specific data must exist at a particular point in time, because only at that moment can the corresponding random hash value be obtained. Each timestamp should include the previous timestamp in its random hash value, each subsequent timestamp enhanced (reinforcing) to a previous timestamp, thus forming a chain (Chain). Proof of workload