Topic: CelesOS Research Institute丨DPoW consensus mechanism-combustible mining and votin (Read 368 times)

The token economy and the blockchain complement each other, while at the same time, the consensus mechanism forms the basis of the blockchain, whom constitutes the basic technical framework of the token economy.
The mainstream blockchain, like Bitcoin, Ethereum, and EOS have all compromised on certain aspects of the "impossible triangle" features.



Bitcoin, as a decentralized digital currency, has sacrificed performance to meet the design requirements of decentralization and security, rendering it the target of highest  attacking cost among all PoW public chains. The ASIC mining machines updates continually and new versions launch, both can continuously improve the computing power of the entire network.

Ethereum 2.0 will use a proof of stake (PoS) consensus mechanism. On the Ethereum network, money can be transfered and smart contracts can be operated, presenting a more complicated application scenario. However, due to its low performance, Ethereum is more prone to get congested.

EOS, as a blockchain application platform, is often suspected of being centralized. EOS uses a delegated proof of stake (DPoS) consensus mechanism. Having 21 super nodes responsible for bookkeeping and block generation, the EOS main network can handle more than 4,000 TPS now. However, due to its small number of nodes, it’s one of the three major public chains that are most easily questioned by the outside world on the "decentralization" feature.

An inefficient blockchain will only be a game in the laboratory, and an efficient blockchain without decentralization will only be taken advantage of by big players.


New generation consensus algorithm DPoW

Is there any consensus mechanism that can achieve a better balance between decentralization and efficiency, and can give miners incentives to invest in hardware resources? If we separate the two acts of "acquiring accounting rights" and "receiving block rewards", the above dilemma can be solved. By separating the above two,  DPoW has finally achieved the effect of balancing efficiency and centralization.

Consensus   Transfer   Verify    Consensus

Drawing on the design concept and operating experience of the preceding consensus mechanisms, DPoW is a new-generation consensus mechanism formed based on PoB and DPoS.

Before explaining DPoW, it’s necessary to introduce PoB.
PoB (Proof of Burn) is called the burning proof mechanism. (Source: https://en.bitcoin.it/wiki/Proof_of_burn)


PoB is a way to vote who has a commitment to the leadership of the network by burning tokens possessed. The greater the number of tokens burned, the higher the probability of gaining network leadership.
PoB is a method of distributed consensus and an alternative method of proof-of-work mechanism. It can also be used to guide a cryptocurrency.



In the DPoW-based blockchain, the miner's mining reward is no longer a token, but a "wood" that can be burned-burning wood. Through the hash algorithm, miners use their own computing power to get the corresponding non-tradable wood after proving their workload eventually. When the wood has accumulated to a certain amount, it can be burnt in the burning site.



DPoW technical solutions

Voting with computing power is the biggest innovation of the present invention. It uses the proof of work of the PoW algorithm to replace the stakes as votes, yet retains the BFT-DPoS block generation mechanism.

Specific steps are as follow:
1. POW question acquisition
Obtain the question of proof of work. The proof of work of the present invention is to perform a Hash operation on a PoW problem; the questions is:
target = hash(block_id + account) ^ difficulty
2. POW question answering
A mathematical hash operation of a random number (nonce) is performed on the question, and if the hash value obtained is less than a certain value, the question is answered;
Question answering process:
nonce = random
()ret = max()
while(ret > target) {   
if(hash(nonce+account + block_id）< target) {       
wood = nonce;       
break;   
}   
nonce++;
}

3. Voting
Voting is to cast the specific answers to the question to the candidate BP. By such, it’s submitted to the blockchain and counted to the blockchain's status database; within an election period, the maximum value of the answer that each voter can calculate is N, and each answer can only be voted to one candidate BP, and the number of votes that can be cast is N.

The information and process that voting requires:
Answer to the question
Miner account
Block id
Block
Voting objects (candidate BP)
Verify that the vote is valid
After verification, it will be credited to BP

4. Count the votes
At the end of an election period, votes are counted and sorted top-down according to the number of votes under the name of the candidate BP. The top X candidate BPs are selected and inserted into the BP list, and the block generating order of the selected BP is written to the blockchain status database.

If X is the number of BPs generated by the system, namely a multiple of 3, it will be set in the genesis block and cannot be changed.

5. Block generation
The DPoW block generation mechanism is the same as BFT-DPoS. The elected BP negotiates a block generation ownership order based on its own network resource status. When each BP node has block generation rights, the block reward is a fixed reward for each effective irreversible block. At the same time, the blocks that have been generated use the BFT signature mechanism. After getting 2/3 BP's signature, the block will become an irreversible block.



advantage in balance

Compared with existing technical solutions, the DPoW consensus protocol has the following feature.
1. When the stock of burning wood is large, the nodes in the system tend to burn burning wood to vote instead of logging through computing power, which is similar to the DPoS under this situation.

2. When the stock of burning wood is few, the nodes in this system tend to log to obtain burning wood for voting, which is similar to PoW under this situation, presenting the feature of decentralization. In order to ensure the high-speed operation of the system and attract ticket sources, BP will maintain a stable investment in computer resources to keep the system highly efficient.

Choosing to vote by logging or burning wood depends on the nodes’ own optimal choice, resulting in constant choosing between the two consensus mechanisms of PoW and DPoS. This will make nodes tend to choose PoW when decentralization is needed, and to choose DPoS when efficiency is needed.
For a system, whether it is decentralized does not depend on whether each block needs to be decentralized. The key is whether the system can provide a channel to decentralization and fair competition when needed. As long as the channel is reasonable, the system will be considered decentralized.
By decoupling vote by logging and block generation, they can be done asynchronously to achieve the effects of decentralization and high efficiency.

Learning and updating the preceding practices in blockchain technology, DPoW manages to achieve both decentralization and efficiency, as “having the cake and eating it”.