A review on healthcare information systems and consensus protocols in blockchain technology
Cleverence Kombe, Mussa Ally Dida, Anael Elikana Sam · International Journal of Advanced Technology and Engineering Exploration · 2018
IntroductionBlockchain technology is a distributed electronic ledger of digital records, events or transactions that are cryptographically secure, extremely hard to forge, and updateable through a consensus protocol agreeable to all connected nodes.[1] The technology uses decentralized consensus algorithms to control database consistency.The database is purely distributed in nature and is shared to all nodes connected to the network.Transactions in the databases are bundled together for specified period of time to form a block of certain number of transactions.These blocks are linked cryptographically through hash pointers to form a chain of blocks with transactions (Figure 1) [1-3].*Author for correspondenceThe technology has a multitude of applications in various sectors including but not restricted to financial services, retail and consumer goods, energy, higher education, transportation, manufacturing, and telecommunication technologies.It can be applied in financial services and contracts including various financial assets, for example derivatives, options, swaps, and bonds.The blockchains are also used to implement applications beyond the financial services industry and in more general-purpose industries such as government, health, media, the arts, and justice [3][4][5][6][7].Blockchains are either permissionless or permissioned.Permis sionless are open-ended systems whereby any node can conduct transactions as well as take part in the consensus process to advance the network.They are publicly available therefore number of nodes are expected to be large, and these nodes are anonymous and untrusted since any node can join the network.Examples of