What is consensus algorithm?

As we know, a blockchain is a decentralized P2P system without central authority figure. Every node in blockchain fetches, reads and stores data in a shared database or record system called as distributed ledgers. These distributed ledgers are shared data records and hence an inherent mechanism to monitor & maintain the data changes is required. Consequently, for any blockchain to consider decisions, it needs to come to a consensus utilising “consensus mechanisms”.In a layman’s term, consensus is a dynamic method to reach agreement within a group. Whilst voting only settles for a majority rule without considering any thought on the feeling and well-being of minority, a consensus on the other side works in making sure about whether an agreement is reached which could benefit the entire group as a whole.

In a more ideal point-of-view, Consensus can be utilized by a group of people scattered around the geography to create a more equitable and fair socio-world.

A process through which consensus decision-making is derived is called “consensus mechanism”. The end objectives of a consensus mechanism are:

• Agreement Seeking: A consensus mechanism brings about maximum agreement from the group to the possible extent.


• Collaborative:  Participants aim to work together to earn a result that puts the best interest of the entire group first.


• Cooperative: Participants put their own interests first and work as a group more than an individual.


• Egalitarian:  A group which tries to achieve consensus will require to be as egalitarian as possible. This implies that each and every vote has the same weight. One person’s vote cannot be more significant than another’s.


• Inclusive: As many parties as possible would be involved in the consensus process. It wouldn't be like routine voting where people don’t actually feel like voting because they understand that their vote won’t have any significance in the long run.   


• Participatory: The consensus mechanism would be such that anyone would actively participate in the entire process.

As per the function and requirement of a particular blockchain application, a particular consensus mechanism can be used. An appropriate use of consensus mechanism ensures efficient implementation of blockchain in a business system