At a technical level, a blockchain can be defined as an immutable ledger for recording transactions, maintained within a distributed network of mutually untrusting peers. Every peer maintains a copy of the ledger. The peers execute a consensus protocol to validate transactions, group them into blocks, and build a hash chain over the blocks. This process forms the ledger by ordering the transactions as is necessary for consistency. Blockchain has emerged with bitcoin (http:// bitcoin.org/) and is widely regarded as a promising technology to run trusted exchanges in the digital world.
A blockchain supporting a cryptocurrency is public, or permissionless, in the sense that anyone can participate without ...
