The Cryptocurrencies along with the Blockchain Technology is most famous for the high-class security that it provides. It is estimated by professionals that, for a hacker, it is easier to break into a Centralised Financial Reserve and rob the funds than to take control of the Bitcoin Blockchain network.
This high-security attribute is obtained through something known as Distributed Ledger Technology and the Consensus mechanism. As the data is distributed among the nodes in the network, the same copy of data is available to everyone, hence tampering the data in some of the nodes will not affect the information on the Blockchain but would be considered as invalid by the majority of the nodes. This consensus of coming to a common point that a set of particular nodes have been tampered with is what that provides Blockchain Technology with its security.
Generally, a consensus is important as it results in impartial benefit for each and everyone, although the decision might not seem to be going hand in hand with each individual’s interest but is the best solution for the overall development of everyone. A number of consensus mechanism have been developed through a number of cryptocurrencies but two of the most popular one is the proof of work and proof of stake consensus mechanisms. Hence one must know the basic differences and similarities between the Proof of Work and Proof of Stake.
The Cryptocurrency Miners, mine the blocks and then present it to the network so that it is added to the network and they receive a Block reward. But the blocks are attached to complex mathematical problems which are highly difficult to solve and uses brute force computations in order to solve them. With time, as the network and the number of miners increases, the difficulty of solving the problems increases too.
A block is then checked for its validity through the proof of work consensus mechanism and if it is found to be invalid by more than half of the members in the network then the block is discarded. Nevertheless, if the hackers gain access to more than 50% of the total network then she/he can manipulate the behaviour and can confirm an invalid block to be valid and hence a tampered block is added to the Blockchain.
In order to avoid this problem, the network size comes into picture which is huge in this case, and is growing day by day, hence gaining control over the members spread throughout the world at such massive scales is near to, but not impossible. It is worth mentioning that, in order to maintain the time taken for the creation of a new block, the difficulty level is automatically incremented.
For a real-time instance, if the network automatically observes that the time taken to add a block on to Bitcoin blockchain network is lesser than 10 minutes then the difficulty is automatically increased so as to compensate the time required for the addition of new block. Basically in this concept, the profitability of mining a block, depends on the amount of work done by the minor hence the name ‘proof of work’.
Even in this consensus mechanism aims at the verification and the addition of a new block to the Blockchain network but considering the amount of money a particular user stakes on a block. Hence the user who possesses the highest amount of stake is more likely to become the next block validator. This method is considered to be far more efficient than the proof of work mechanism but it is not being used that widely.
The Proof of Stake mechanism is considered to be eco-friendly as it does not require huge amounts of energy consumption and is also healthy for the network’s development too. One of the key features in the Proof of Stake consensus mechanism is that all the coins in the network are pre-mined. There is no creation of new coins and hence the minors are rewarded with the complete transaction fees of the transactions they verify.
Forking a particular Blockchain is not good for the development of a network, intense experimentations were done by the researchers on the proof of work mechanism which led to the conclusion, that it restricts the forking process which in turn leads to an instability in the network, as the miners would have to distribute the computation power between the old and the new Blockchain. When compared to the proof of the Stake mechanism, as it does not require Brute Force power, forking a particular network doesn’t affect the consensus mechanism at all.