Cryptography does more than obfuscate information. In this Economist article, we read about, "Blockchains are also the latest example of the unexpected fruits of cryptography." Blockchains enable Bitcoin to operate without central management or authorities. A blockchain is a public ledger of all transactions that have ever been executed in a system. A block is the “current” part of a blockchain which records some or all of the recent transactions, and once completed, goes into the blockchain as a permanent entry.
Mathematical scrambling is used to boil down an original piece of information into a code, known as a hash. Any attempt to tamper with any part of the blockchain is apparent immediately—because the new hash will not match the old ones. In this way, a science that keeps information secret (vital for encrypting messages and online shopping and banking) is, paradoxically, also a tool for open dealing.... A trusted private ledger removes the need for reconciling each transaction with a counterparty, it is fast and it minimises errors.
Peer to Peer file sharing networks removes the need for centralized databases and heavy storage areas. Think BitTorrent or distributed cloud storage. An increasing number of organizations and political parties have proposed the creation of a blockchain-based system to build a fairer and more transparent voting environment. The Danish political party, Liberal Alliance, proposed using this approach for e-voting.
Anything where an accurate record is needed, a blockchain can be useful. This could be included in the hash to any file, for a record. Instead of having a central source keeping track and controlling the flow of information, all communications are agreed upon through a consensus of all nodes in the network.