The bitcoin is the first cryptocurrency known to have implemented the principle of blockchain .
it is necessary to dissociate Bitcoin and bitcoin, the first being the peer-to-peer network on which the transactions are performed and the second, the unit of account which is the object of constant exchange on the Bitcoin network.
Bitcoin was invented by Satoshi Nakamoto in 2009 and which itself inspired a first aborted attempt to create crypto-currency named b-money (somehow the ancestor of bitcoin) . Bitcoin was created in order to provide a decentralized payment system that frees up financial institutions (banks) acting as intermediaries in monetary transactions.
indeed in a world where Internet shopping is becoming more frequent, it was necessary according to Satoshi Nakamoto to provide a faster, cheaper and more secure solution (piracy being a real wound for payments made by credit card).
Double-expense problem (Double Spending)
Bitcoin was able to see the light of day thanks to the resolution of the problem of double expenditure.
If a user A sends bitcoin to a user B , it is necessary to be able to ensure that once the bitcoin is spent, they can not be again by user A (who could send them back to a C user for example).
it was then that the establishment of a consensus system to validate the blocks containing the transactions.
to get Satoshi Nakamoto was once again inspired by a already existing work proof system named "HashCash" and which originally allowed to fight spam as well as DDOSS attacks ( Denial of service).
a work-proof system (or consensus system) ensures that a certain amount of resources have been solicited before a task is completed.
in the case of Bitcoin it is for the miners of the network to solve a complex mathematical problem (using the processor of their computer) which once solved leads to the validation of the transactions of a new block and adding the latter to the blockchain registry .
solving the problem of double spending makes it possible to give a unique character to every bitcoin circulating on the network, because they cannot be duplicated as simple computer files.
knowing that the maximum attainable amount of bitcoin is 21 000 000 units.
End of intermediaries (decentralized network)
The Bitcoin network works according to the peer-to-peer model , in clear there is no central node that centralizes transactions on the network.
No intermediary allows:
- To ensure faster transactions anywhere in the world thanks to the Internet network
lower transaction fees
- A decentralized network that operates 24/7 and without human intervention (it can be said that to prevent the Bitcoin network from functioning it
would be necessary to disconnect the Internet).
Bitcoin mining (securing the bitcoin network)
the activity that allows to secure the Bitcoin network (and avoid the problem of double spending) is called "mining " and consists for miner dinners (Special nodes of the Bitcoin network) to validate all new bitcoin transactions made by users .
This means that all transactions made on the bitcoin network must be grouped together in a block and then validated by miners.
these miners must solve a mathematical problem, which once resolved triggers the validation of the block being created. Every time a miner manages to solve the mathematical problem it is renumerated in bitcoin .
in clear the creation of new blocks containing new transactions rests a work effort (proof-of-work) on the part of the miners.
it is therefore impossible for anyone to add their own transaction block without the validation of the latter by miners verifying that the block is valid.
If the block is not valid it is rejected and not added to the blockchain registry of the bitcoin .
to go further in your understanding of bitcoin, I recommend reading the whitepaper which was written by its creator Satoshi Nakamoto.