Anyone can view the contents of the blockchain, users can also choose to connect their computers to the blockchain network as nodes. By doing this, their computer receives a copy of the blockchain that is updated automatically whenever a new block is added, sort of like a Instagram feed that gives a live update whenever new content is posted.
Every computer in the blockchain network has its own copy of the blockchain, this means that there are thousands, or in the case of the Cryptocurrency – Bitcoin, millions of copies of the same blockchain. Although each copy of the blockchain is identical, spreading that information across a network of computers (nodes) makes the information extremely difficult to manipulate.
With blockchain, there isn’t a single, definitive account of events that can be manipulated. Instead, a hacker would need to manipulate every copy of the blockchain on the network. This is what is meant by blockchain being a “distributed” ledger.
Looking over the Bitcoin blockchain, however, you’ll notice that you don’t have access to identifying information about the users making transactions. Although transactions on the blockchain are not totally anonymous, personal information about a user is limited to their digital username or signature.
This raises an important question: if you cannot know who is adding blocks to the blockchain, how can you trust blockchain or the network of computers upholding it? This is a question will answer as the blog develops.