what is blockchain?

The blockchain is an information storage and transmission technology, transparent, secure, and operating without a central control organ.
By extension, a blockchain is a database that contains the history of all the exchanges made between its users since its creation. This database is secure and distributed: it is shared by its different users, without intermediaries, which allows everyone to check the validity of the chain.

There are public blockchains, open to all, and private blockchains, whose access and use are limited to a certain number of actors.

A public blockchain can therefore be likened to a large public accounting book, anonymous and unfalsifiable. As the mathematician Jean-Paul Delahaye writes, one must imagine "a very large notebook, which everyone can read freely and freely, on which everyone can write, but which is impossible to erase and indestructible. "

Locate the blockchain:

The first blockchain appeared in 2008 with the bitcoin crypto currency, developed by a stranger appearing under the pseudonym Satoshi Nakamoto. It is the underlying architecture.

If blockchain and bitcoin were built together, today many actors (companies, governments, etc.) are considering the use of blockchain technology for other cases than crypto currency.