Introduction Blockchain is a decentralized database or a distributed ledger that holds transactions. A blockchain is typically distributed over a peer to peer network where each node in the network hold identical real-time copy of their ledger. A block in a blockchain is similar to a page in a ledger. It may represent a transaction/contract/certificate of ownership/state of authenticity/proof. Each block in the blockchain is linked to the hash of the previous block. Once a block is chained it cannot be modified or removed from the chain. There can be two ways to corroborate the accuracy of the ledger. Permissioned (where participants that contribute are preselected) Unpermissioned (where anyone can contribute) Unpermissioned ledger Anyone can contribute to the ledger. In bitcoin, the actors can contribute through a process called mining. This means that no single person has control over any transaction. Permissioned ledger When a new record is added, ...