One of the core parts of a blockchain network is the consensus protocol. Blockchain is known to be a distributed decentralized network; there is no central authority in charge of validation and verification of transactions. The consensus protocol made it possible for the transactions on the blockchain totally secured and verified.
Image source: cryptovest.com
CONSENSUS ALGORITHM
A consensus algorithm may be defined as the mechanism through which a blockchain network reach consensus or common agreement. The consensus algorithms are a significant strand of every blockchain network as they are superintended for sustaining the security and integrity of the blockchain. The consensus protocol makes sure that every new block that is added to the Blockchain is the one and only verified and validated version that is agreed upon by all the nodes in the Blockchain. Consensus algorithms exist to mitigate the "double-spend" attack, where a malicious actor is able to spend the same coin any number of times. the consensus algorithm in any blockcahin is designed to solve the issue of trust between the participants of a network. The consensus algorithm is the final piece that makes cryptocurrencies work.
Image source: cisin.com
PROOF OF WORK CONSENSUS
It is not a myth that Bitcoin and some other notable original cryptocurrencies like ethereum,Litecoin,Dash and Digibyte were born as pure proof-of-work systems. The Bitcoin and Digibyte communities remain some of the devoted patrons of mining and proof-of-work. The proof of work consensus algorithm is employed to certify transactions and build new blocks to the chain. it involves solving a computational challenging puzzle. Colloquially, the process is known as 'mining', and the nodes in the network that participate in mining are known as 'miners'. When a miner finally finds the right solution, the node broadcasts it to the whole network at the same time, receiving a reward provided by the PoW protocol. The main benefits are the anti-DoS attacks defense and low level impact of stake on mining possibilities. But if the mathematical problem is too easy then the network becomes prone to vulnerabilities, DoS attacks and spam. Accurate work and speed of Blockchain system is dependent on this consensus. The proof of work consensus comes with its own flaws which are:
· A 51 percent attack, which occurs when a user or a group of users control the majority of mining power. The attackers get enough power to control most events in the network, potentially causing a network disruption. In storyline, the attacker would have enough mining power to purposefully prohibit or modify the ordering of transactions. They could also alter transactions they made while being in control which can result In a double-spending hitch.They can takeover the generating of new blocks and receive rewards since they're able to shut out other miners from completing blocks.
· PoW is also energy intensive. It's costly and requires plenty of computing power Mining requires highly specialized computer hardware to run the complicated algorithms. This specialized computer hardwares are not cost friendly.
Other protocols have come into being to overcome the setbacks and flaws of PoW, especially to reduce the high energy consumption of the PoW algorithm. And for the fact that mining requires as much as tens of thousands of dollars in equipment, electricity and optional hosting expenses. One possible solution that has already been deployed in the digital currency ecosystem is the Algorand's permissionless and PURE PROOF OF STAKE, with the motive of shifting away from proof of work, but still maintaining the principles of a non-centralized systems.
ALGORAND CONSENSUS PROTOCOL
Algorand consensus mechanism is permissionless and PURE PROOF OF STAKE, first of its kind. The mechanism ensures full participation, protection, and speed within a truly decentralized network. With blocks finalized in seconds. Algorand is the first blockchain to provide immediate transaction finality without forking nor uncertainty. Algorand's pure proof-of-stake (PPoS) protocol is built on Byzantine consensus. Users are arbitrarily and secretly picked to both propose blocks and vote on block proposals. All online users have the odds to be chosen to propose and to vote. individuals's impact on the choice of a new block is in proportion to its stake in the system. Algorand's PPoS technique ties the security of the entire economy to the honesty of the bulk of the economy, rather than to that of a miniature portion of the economy. In Algorand, it is not possible for the possessors of a tiny percentage of the money to distress the whole system, and it would be mindless for the owners of the majority of the money to act up as it would shrink the currency's purchasing potentiality and ultimately depriciate their own assets. The Algorand blockchain is absolutely decentralized, which means there is no supreme or dorminant authority. Users are not opened to risk of data being manipulated, lost or destroyed, Control is distributed among all individual network participants.
Written by Musa Aminu Bio- Algorand Ambassador.