Bitcoin here, NFT there, surge in cryptocurrencies or obscure traffic on the ugly Dark Web, all these buzzwords are based on the same technology: blockchain or block chain. Here are five points to remember.
First of all, what is blockchain? In good French, we should speak of “block chain”. Clearly, it is a database shared between several computers where each data block contains the digital fingerprint of the previous block. The blockchain contains in itself a history of all the transactions that form it and guarantees the impossibility of rewriting them a posteriori.
Imagine computers linked together in peer-to-peer, whether they are identified (for a private blockchain like that of notaries) or completely anonymous (for a public blockchain like those supporting the main cryptocurrencies, including bitcoin). These computers perform operations to create new blocks, either by encoding information into them, or by circulating older blocks.
Each new block created begins with a footprint calculated from the previous version. For this, a public function, called a hash function, is used. This associates a unique fingerprint with each file in the form of a series of characters. It is therefore impossible to find two files with the same fingerprint! And to prevent manufacturing a second blockchain that claims to substitute for the “real one”, the management protocol requires “proof of work”. This is an operation which associates a single result with any input value, which can only be obtained by carrying out a long calculation. On the other hand, the reverse operation making it possible to check that a given result is indeed that of the associated value is very fast.
What is the advantage of blockchain?
This technology guarantees, without the need for a central element, the uniqueness of tokens (token) IT (the famous NFT), when IT is based on copying: a file, whatever it is, can be copied, distributed, modified … The blockchain is therefore a method making it possible to create this uniqueness in IT, because each copy is identified as such and precise where it comes from.
To take the best-known example, bitcoin, this means that there is no need for a central body (the European Central Bank for the euro, or the US Treasury for the dollar) to validate the currency. created and determine the number of units in circulation. From its creation, each bitcoin is registered in the blockchain and it is possible to trace its date of creation (or mining) and to know where it circulated, and all this without human intervention.
And its drawbacks?
If the most famous application of the blockchain, cryptocurrencies, is surrounded by a sulphurous reputation due to the lack of state control for the most famous of them (bitcoin, Ethereum, etc.), their volatile prices and their implications in transactions that are not always legal, the blockchain itself is not responsible.
On the other hand, it suffers from two problems linked to its very principle of operation: a calculation time that is too slow for certain applications (such as electronic voting, which sometimes requires several hours to validate a single ballot in this way in the experiments in progress. ) and high energy consumption. Indeed, each operation on the blockchain requires the execution of a proof of work. The larger this operation, the more it requires a complicated calculation that consumes time and energy resources.
In some blockchains, such as bitcoin, the more proof of work one of the participants brings, the more currencies he creates (and therefore gets richer). Some are creating veritable “bitcoin mines”, wells without electricity consumption funds. The Digiconomist site thus estimates the electricity consumption of mining in August 2021 at 150 terawatt-hours per year, i.e. Ukraine’s electricity production, or 0.60% of all world electricity production.
But what is the blockchain for?
In addition to virtual currencies which use it both as a “printing press” and as a circulation network, the blockchain, by allowing the recording of unique and tamper-proof information, has many uses. It can be used to identify and authenticate, as with Citizen Ticket, a British booking site that registers each ticket sold on a blockchain in order to validate it and ensure that it is unique.
It can also be used to guarantee the uniqueness of a work of art or digital good (as in the case of NFTs), or even serve as a source of funding for a TV series, such as the animated series. Krakopolis, by integrating a mix of unique works, GIFs and places for special sessions dedicated to fans who are also the miners of this blockchain. Some, such Breedr are used to trace the lineage of livestock, and the notaries of Île-de-France are experimenting to register notarial acts there.
Another example of the use of the Blockchain: real estate. In Georgia, Ghana or even Sweden, all changes made to the cadastre (a change in ownership or destination of a parcel from agricultural land to building land) are recorded on blockchains to avoid any fraudulent modification. The fields of application of the Blockchain are already diverse and varied. And that’s just the beginning.