A blockchain is a distributed ledger consisting of blocks. Each block contains multiple verified transactions. Blocks contain a secured hash, which is generated considering the index, timestamp, data inside the block, and the hash of the previous block. Such a design makes a blockchain auditable and immutable. Any modification to the blocks, after a verified block has been added to the blockchain, would generate a new hash which will be inconsistent with the hashes that precede.
Governments across the world is thoroughly testing the technology and has initiated several pilots solutions using blockchain to build a better, transparent and efficient governance process. Government of India has also shown interest with Blockchain technology while several implementations and pilot programs has been started at State level as well as Central Government level.