Democracy in Blockchain — Why DPoS came into the scenario
Consensus Overview — How consensus is achieved in a network
The miner network is appointed to legalise all transactions in a blockchain and are paid for their service. The miners especially bitcoin miners implement the PoW mechanism to legalize blocks. Proof of Work mechanism requires the miner to solve a cryptographic puzzle in order to find the nonce (explained in our earlier paper, here). Now this feat demands some hardware power, GPU’s to ASIC cards. The problem with graphics hardware is very simple, they are expensive. Even if you buy them this doesn’t solve your problems, you still have to look at that enormous electric consumption bill. Power consumption, expensive hardware, cooling expenditure everything adds upto to a consensus mechanism that instead of filling our pockets with transaction fees and bitcoins, actually takes a toll on it. And that’s not the last of all your problems.
The bigger problem is the people who could actually afford the equipment were potentially going to be the king’s in the network and also sometime might turn to tyrants, and threaten a 51% attack. A 51% attack is when a single miner or pool own 51% of the total network and can now regulate the system on their will. Approving and disapproving on will. Well yes that would be nightmare!
Ok let’s get this straight, the network which was supposed to bring decentralization by removing centralized authorities like banks, from regulating the cash flow and transactions, actually becomes centralized itself if some miner could get his hands on the hardware.
This threat was not something ignorable as it could somewhat destroy the whole blockchain net work and some other form of consensus mechanism was required to get things even.
Enter Delegated Proof of Stake.
Delegated proof of stake is rather an evolved version of Proof of Stake consensus mechanism (find further details about PoS in our previous article, here), which involved the miners collecting stakes after mining and was also believed to lead to a 51% attack.
I know right…uuuuuuuurghhh!
DPoS was developed by Daniel Larimer, for his blockchain based application Bitshares in 2013. The Dpos algorithm was developed with an ambition to bring democracy with the blockchain network. It is a very simple but brilliant concept. It is so designed that the members of the network can appoint witnesses who through a voting mechanism, and it is their responsibility to sign the blocks that are to be added to the the chain. The blocks must be signed only if they match certain criterias as following,
- They have to check whether the previous witness has signed the block or not
- If they don’t produce blocks they could get fired and also lose profits in the future
To understand the concept of this method we need to understand its origin–Bitshares.
For the regulation of the network, the Dpos system appoints some privileged delegates who have the authority to all network parameters, from fee scheduling to block intervals and transaction sizes, all can be tuned via these delegate accounts.
So what are these delegate accounts and how do they regulate the system
Witnesses are elected by the stakeholders and are paid for their services of producing a block. The pay rate is set by the stakeholders via elected delegates, failing to produce a block, payments are stopped and the witness is voted out.
To keep the database of witnesses updated with active members, once every maintenance interval, the votes of stakeholders are tallied . After tallying the list of witnesses are reshuffled and they are given a block to be produced with a 2 sec time frame, failing which the time frame and block is skipped to the next witness for the next block. The witness participation rate also gives away the health of the chain. If participating witnesses number falls below a stipulated mark , the stakeholders can extend the time frame to produce more blocks to increase network strength.
Democratic model of Governance
The Dpos system divided the network participants into three categories, witnesses, stakeholders and delegates.
Stakeholders are the original users of the network, who own stakes.Witnesses are the people elected by them to perform the generation of blocks in return of payments. Finally to understand delegates we will take example of a democratic model of governance.
A democratic model has voters who are the citizens, ministers or delegates who are elected to put the citizens requests infront of the council which makes the decisions. The council might accept or reject the changes and its direct effect would fall on the citizens. The ministers only put forth suggestion or petitions.
So now comparing this model with the Dpos consensus model, citizens would be the stakeholders ,and ministers would be the delegates who put up petitions to the council which are the genesis accounts.
Genesis accounts are those are regular accounts of stakeholders with extra feature or privilege of being able to change network parameters. They can change transaction fees, block sizes, witness pay and block intervals.
The delegates put up suggestions to the genesis accounts and if accepted or even rejected , the stakeholders have the final approval.
Addressing the Double spend attack
The double spend attack can be anytime a transaction previously excluded is included, in simpler terms, if someone spends an extra token which is not owned by him. This might also occur if the witness has a communication breakdown and loss of connection. In DPoS a communication breakdown that could lead to a double spend attack is very low. The health of the network is continuously monitored by the calculating the active witnesses. If a witness cannot deliver in scheduled time due to loss in communication or some other reason. When this happens the participants are to wait for atleast half of the witnesses to to have confirmed their transactions, which could take a minute or two.
This post was cited from the Coincentral.com
“That’s all folks”
Like what you read? comments and let us know
Put up suggestion for topics and questions to discuss.
Follow us on facebook, twitter or subscribe to our telegram channel.