| dc.description.abstract | Blockchain and cryptocurrencies are drawing more and more attention among the people,
due to the overwhelming success of Bitcoin in the market. The success and popularity of
Bitcoin mainly focuses the underlying blockchain technology which is totally immutable
distributed ledger, highly secured by its P2P network consensus named Proof of Work
(PoW). One of the worst threats to a Proof-of-Work based cryptocurrency is 51% attack.
If one or more dishonest network peer gains more than 50% of resource such as
processing power, then they will become the majority decision maker in the network.
Because in this kind of network, peers are competing for faster processing. The peers who
have more processing capabilities can mine more blocks than others. They can easily
manipulate the block chain by creating fake transactions, fraud other users even cause
large scale financial damage to the exchanges. We’ll describe this majority attack in
detail in chapter 2. There are several researches have already been done on how to
prevent this attack and most of them suggest mixing of two or more proof of resource to
form a hybrid protocol to tackle this attack. It is already proved that mixing of two or
more existing protocol that is called hybrid protocol can make the network enough
resistive to this attack. The recent implementations of hybrid protocols have other
limitations and problems that they are facing and striving to resolve. Some of them
introduce voting system, ticket distribution system, penalties, special nodes and block
validator groups for preventing the malicious activities. All these implementations are
successful to protect the network from 51% attack. But their main weakness is in
distribution of block mining reward to the investors. From the perspective of an investor,
an investor invests his hard-earned money in a cryptocurrency for making proper profit
from his investment. The main source of this profit is the block reward which is generated
and given to the miner on successful mining of a block. So, to ensure this profit is given
to proper user on proper time interval, the consistency of block generation time interval is
a vital factor. The voting system, ticket system etc. are not time controlled and over all
block reward generation interval will not show a uniform distribution of profit. Another
big issue is diversifying the peers by creating special committee and groups of validators
the concept of P2P network is violated. In this paper we’ll describe a step by step process
to implement a Hybrid PoW-PoS based consensus protocol. In our proposed system, the
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PoW mining process is only used to regulate the block generation time. The actual block
generation is done by the same user with PoS consensus mechanism. There is no voting
or validating committee. The entire network will validate each block. This is the major
difference with other discussed system. The system will not only be able to tackle the
51% attack, it provides a uniform distribution of mining reward to the stake holders and
investors by maintaining a precise block generation interval with difficulty adjustment in
PoW mining and probability calculation for stake holders according to their matured
staking balance. We’ll not only show how to make the system non-vulnerable to this
attack but also describe in detail about how to validate the transactions and blocks in
different stage of creating the block chain | en_US |
