Blockchain and the Public Ledger

Blockchain was originally the technology that powered Bitcoin, but it has greater scope than that. It is a digital ledger of transactions where the data is stored in batches called blocks that are distributed to many computers. Therefore, if you wanted to tamper with the blockchain, it would be impossible as you would have to change the data on every computer holding a copy. As they say, there is safety in numbers.

Blockchain can be used to store financial, medical, or land sale transactions. This data is chained together with a block of data holding both the hash for that block and the hash of the preceding block. To create a new block on the chain, the computer that wishes to add the block solves a cryptographic puzzle and sends the solution to the other computers participating in that blockchain. This is known as proof of work. Once that has been verified by those computers on this network, a new block is added to the end of the chain. Should...