What is the Work Test?
Proof of Work, or PoW (for its acronym in English), is the original consensus algorithm in a Blockchain network.
In Blockchain, this algorithm is used to confirm transactions and produce new blocks in the chain. With PoW, the miners compete among themselves to complete online transactions and obtain rewards.
In a network, users send each other digital tokens. A decentralized database gathers all transactions in blocks. However, care must be taken to confirm the transactions and organize the blocks.
This responsibility is based on special nodes called miners, and a process is called mining.
The fundamental working principles are a complicated mathematical conundrum and the possibility of easily testing the solution.
What do you mean by a "mathematical puzzle"?
It is a problem that requires a large amount of computing power to solve.
There are many of them, for example:
hash function, or how to find the entrance knowing the exit.
factorization of integers, in other words, how to present a number as a multiplication of two other numbers.
guided puzzle protocol. If the server suspects a DoS attack, a calculation of the hash functions is required for some nodes in a defined order. In this case, it is a problem of 'how to find a string of hash function values.'
The answer to the problem of PoW or mathematical equation is called hash.
As the network grows, it faces more and more difficulties. Algorithms need more and more hash power to resolve. Then, the complexity of the task is a sensitive issue.
How?
The precise work and speed of the Blockchain system depend on it.
But the problem should not be too complicated. If it is, block generation takes a long time. Transactions are blocked without execution and, as a result, the workflow is blocked for a while. If the problem can not be solved in a defined period of time, the generation of blocks will be a kind of miracle.
But if the problem is too easy, it is prone to vulnerabilities, DoS attacks and spam.
The solution needs to be reviewed easily. Otherwise, not all nodes are able to analyze if the calculations are correct.
Then you will have to trust other nodes and that would violate one of Blockchain's most important characteristics: transparency.
Four.
How is this algorithm implemented in the Blockchain?
The miners solve the puzzle, form the new block and confirm the transactions.
The complexity of the puzzle depends on the number of users, the current power and the network load. The hash of each block contains the hash of the previous block, which increases security and avoids any block violation.
If a miner manages to solve the puzzle, the new block is formed. Transactions are placed in this block and are considered confirmed.
