What is Blockchain ?
Blockchains are incredibly popular nowadays. But what is a blockchain? How do they work, what problems do they solve and how can they be used? Like the name indicates, a blockchain is a chain of blocks that contains information. This technique was originally described in 1991 by a group of researchers and was originally intended to timestamp digital documents so that it’s not possible to backdate them or to tamper with them. Almost like a notary. However it went by mostly unused until it was adapted by Satoshi Nakamoto in 2009 to create the digital cryptocurrency Bitcoin. A blockchain is a distributed ledger that is completely open to anyone. They have an interesting property: once some data has been recorded inside a blockchain, it becomes very difficult to change it. So how does that work? Well, let’s take a closer look at a block. Each block contains some data, the hash of the block and the hash of the previous block. The data that is stored inside...