Since the development of the blockchain in 2009, a variety of consensus mechanisms have evolved. The consensus battle over algorithms continues to evolve. Although the "new consensus algorithm" with many latecomer advantages is solving some problems in the previous consensus algorithm, it also exposes other problems. There is no consensus algorithm that is a panacea for all diseases.
As for the dispute over consensus, we can now give a conclusion: "There is no perfect, only the most suitable."
As we all know, in the various discussions of the "impossible triangle", the result of decentralization often means inefficient TPS, and the massive data of the Internet of Things has become a huge stone that cannot be removed in the construction of consensus. So in the field of blockchain + IoT, what is the right consensus? Let's start with the evolution of consensus algorithms.
Evolution of Consensus Algorithms
At present, most of the blockchain consensus comes from the "BFT family", "Proof of X family", or a combination between the two major families.
In the field of blockchain, although we most often hear POW or POS, BFT (Byzantine Fault Tolerance Consensus) is definitely an earlier consensus mechanism in the field of distributed computing, and due to its poor scalability and other problems, the application scenarios are limited.After the birth of the blockchain, the BFT consensus has also been revitalized. It is mainly used in the permission chain and can also be applied to the public chain after modification, such as many later developed DBFT and PBFT. The LibraBFT consensus adopted by Libra is also based on the new BFT consensus HotStuff.
Proof of X is a type of consensus that is widely used in the public chain field. PoW was the first one to be applied, but there were some problems like waste of resources, concentrated hash rate, lack of finality, and poor performance.
PoS is currently a strong competitor, and it can avoid problems of waste of resources, weaken the demand of the central mining pool, and reduce the possibility of attacks by 51%, but it also has difficulties in determining the number of bookkeeping nodes, the problem of unintended centralization and Nothing at Stake.
In order to solve the shortcomings mentioned above, many hybrid consensuses which are hoped to combine the advantages of the two and avoid certain shortcomings have also been discovered, including PoW + PoS, DPoS + BFT, etc. Therefore, the hybrid consensus mechanism may be an outlet for the later development of the public chain.
PoW Consensus Algorithm
PoW (Proof of Work) is the proof of workload. The digital currency is allocated according to the workload of the miner. The higher the performance of the miner, the larger the number, and the larger the workload.
BTC is the most typical example of the PoW scheme. It involves solving a mathematical problem through the mining process, and the miner has completed the PoW through this technical means to obtain the right to book. Because it requires computing resources, successful miners are rewarded with BTC.
In order to control the monetary base, mining has been set to a more complex model. Because the probability that each miner solves a problem depends on his hash, the difficulty of mining is determined by the sum of all hash rate in the system. For cryptocurrencies with the PoW mechanism, miners confirm and fix transfers by competing to solve mathematical problems. The first miner to solve the problem was rewarded. The complexity of this problem is deliberately created to control the monetary base.
This process is considered to be a genius act as it solves the Byzantine general problem well. But others have criticized it for being inefficient because it lost resources for nothing. At the same time, the single PoW mechanism also faces security issues such as 51% hash rate attacks.
With the development of BTC and the blockchain industry, the shortcomings of the PoW mechanism have also been exposed. Currency holders cannot participate in any decision-making, and the discourse right is concentrated in the hands of miners. This runs counter to the concept of decentralization, and the decision-making power is concentrated in the hands of a few miners.
At the same time, PoW faces the problem of high participation costs. An investor who is new to digital currency will rarely have the energy to manage and lay out miners so that most users and currency holders cannot participate in decision-making, making the power too concentrated. Bitmain is an example. Its hash rate can already control the entire network in the dark.
The following will discuss several prominent issues of the PoW algorithm.
Waste of resources
The PoW consensus process is highly dependent on the hash rate contributed by the blockchain network nodes. These hash rates are mainly used to solve SHA256 hash and random number search, and do not actually generate any effective social value.With the increasing popularity of encrypted digital currencies and the emergence of professional mining equipment, the encrypted digital currency ecosystem has shown a clear "arms race" in capital and equipment, and has gradually become a capital-intensive industry with high energy consumption, further highlighting the issues of resource consumption.According to data from some foreign websites, if you consider Bitcoin and Ethereum as a country, the total power consumption of mining has already exceeded Algeria, Israel, and Greece, ranking 45th in the world.
Looking at Ethereum alone, the total electricity consumed by mining exceeds that of countries such as Macedonia, Honduras and Angola, which consumes about 8.63 trillion watt-hours of electricity annually, accounting for 0.04% of the world's electricity consumption.
Concentrated Hash Rate
The premise of Satoshi Nakamoto's design of the PoW consensus mechanism is the uniform distribution of hash rate and computing nodes. However, as the number of bitcoins decreases, the demand for hash rate increases, and people begin to accelerate the acquisition of bitcoin through joint mining, which has led to a new method of mining pool mining. The emergence of mining pools has to some extent disrupted the balance of cryptocurrency systems such as Bitcoin, and the Matthew effect has gradually emerged.
According to the data from btc.com, BTC.com, AntPool, SlushPool, ViaBTC and BTC.TOP, which ranked among the top five mining pools in the past year, accounted for 64.6% of Bitcoin's total hash rate share.Theoretically, the five mining pools together have indeed the ability to launch a 51% hash rate attack. In fact, the cost of these mining pools to master 51% of the hash rate of the entire network far exceeds the benefits of successful attacks, but the security threat of 51% attacks always exists, raising concerns about the concentration of hash rate.
Poor Business Processing Performance
In other words, based on the consensus of PoW, TPS is generally low. Although the PoW consensus algorithm has invested a lot of energy to support the operation of the system, most of these energy consumptions are used for hash operations in proof of work, and the performance of the blockchain network for processing transaction services (TPS) is very low. For example, Bitcoin can only make about 1 * 1024 * 1024/250 / (10 * 60) = 6.99 transactions per second.
DPoS Consensus Algorithm
DPoS is a new consensus algorithm based on PoW and PoS that guarantees the security of digital currency networks. It can not only solve the problem of excessive energy consumption of PoW during the mining process, but also avoid the "trust balance" bias problem that may arise under the distribution of PoS rights and interests. Therefore, DPoS can logically become the representative consensus mechanism that consensus mechanism 3.0 stands out from. DPoS can allow users to participate in mining widely, which means that each holder can vote, resulting in a certain number of representatives, or understood as a certain number of nodes or mining pools, between them the rights are exactly equal. Holders can replace these representatives by voting at any time to maintain the "long-term purity" of the system on the chain.
We can understand the meaning of the DPoS consensus system with the National People's Congress representative system in China. When elected NPC deputies can no longer perform the duties entrusted to them by the people (of course, in the blockchain system, they are unable to maintain the entire network operation process), they will be removed and the network will Re-elect new representatives to take their place.
The advantage of DPoS is that it can minimize the energy consumption of maintaining the network operation, and manage the operation of the entire chain in a low-cost way, which has largely solved the energy consumption problem of PoW. At the same time, a more "decentralized" management method will decentralize the decision-making power of the blockchain network to all nodes in the entire network, which largely avoids the "holding" phenomenon that is easily manipulated by dealers in PoS. The emergence of the DPoS consensus mechanism will improve the efficiency of network-wide operation and maintenance by counteracting the negative effects of "centralization" through the implementation of "democracy" on the blockchain and the publicly-selected "weak centralization".
PoW + DPoS Hybrid Consensus Mechanism
PoW + DPoS's hybrid consensus mechanism allows DPoS to maximize the audience. Referring to the super nodes of EOS, first of all, this is reflected in the real benefits. According to the EOS white paper, EOS will issue an additional 1% of tokens to people who maintain nodes each year. The total amount of EOS is 1 billion, and 1% is 10 million EOS. According to the unit price of 40RMB, it is a total of 400 million, and it is distributed to 21 nodes. Each node still has a revenue of nearly 20 million each year. Don't forget, the above is the price estimated at 40RMB. It is cannot be accurately estimated how much EOS can rise in the future. Once the price takes off, the future earnings of these super nodes are inestimable.
The second is about the world status of the blockchain. Becoming an EOS super node will also become the "first-level agent" of the EOS network, with voting and speaking rights in the EOS ecosystem.
The advantage is the benefit of the DPoS mechanism, and when the network is unstable, the PoW mechanism can make up for shortcomings in the early stages of network operation. The hybrid mechanism of PoW + DPoS achieves the complementarity of the two consensus algorithms, which are similar to the hybrid consensus mechanism with PoW + PoS.
Compared with the entire BTC participating group, BTC miners account for only a small part of the number, and most of the rest are BTC investors and users, which does not play a positive role in the development and stability of BTC.
The innovative nature of this hybrid consensus mechanism is to allow both users and miners who hold tokens to participate in voting and jointly participate in major decisions of the community.Consensus results are widely recognized without developer intervention, and this is truly relative decentralization.
The community of the blockchain adopting this hybrid consensus scheme can better achieve the following goals:
- participative
- collaborative
- cooperative
- distributed
- decentralized
- autonomous
These 6 characteristic high-efficiency communities use a hybrid mechanism to achieve the efficient operation of the Decentralized Autonomous Organization in a broad sense. This hybrid mechanism allows holders of digital currencies to directly participate in major project decisions without the need to purchase expensive miners.
In general, through PoW, BigBang Core has the hard cost of mining as a guarantee for the price of the currency. Miners will hardly sell tokens below the cost price, and with the increase of hash rate, rising mining costs will not only keep the price of coins in a stable and upward state, but restrict the problem of excessive concentration of tokens in the separate DPoS mechanism.
On the other hand, DPoS allows small and medium investors to focus on the medium and long-term development of the project. Small and medium-sized investors are more inclined to put coins in their wallets for DPoS instead of placing them on the exchange at any time to prepare for trading. This makes the BigBang Core ecosystem healthier, and people will pay more attention to the technology and landing applications of IoT data on the blockchain, such as BigBang Core, rather than just focusing on short-term price fluctuations.
Therefore, both PoW miners and DPoS miners can participate in the system consensus and being important roles.
PoW+PoST+PoRep Mine
At present, almost all mining machines are wasting resources, not only PoW consumes power, even storage mines under PoST / PoRep consensus are idle, idle CPU, bandwidth, memory and storage capacity. Because PoW itself has a design defect that consumes a lot of resources, and PoST / PoRep does not have data that can be stored because there is no landing application scenario, mines produced under different consensus have fatal design flaws.
In the IoT public chain developed by the BigBang Core team, three kinds of consensus are introduced to solve the above problems at the same time.PoW can allow miners to accelerate Solo through hardware acceleration methods such as FPGA to make the Token distribution more dispersed, while later CPUs and FPGAs can serve and accelerate data distribution, indexing, and challenge verification. Moreover, after the DPoS runs on a large scale PoW calculation also has a certain probability to obtain rewards for main network block production, and it can also prevent the overall blockage of the block network due to collective strikes by DPoS nodes; the storage capacity and bandwidth of the miner itself can provide massive data for the IoT direction. Data storage capabilities, and all mining machines can obtain token incentives through data storage, data distribution, data indexing, challenge verification and other methods.
Therefore, the combination of PoW + PoST + PoRep consensus is exactly the right hybrid consensus combination, without waste of resources, and at the same time it can achieve the on-chain and indexing of massive data, and release and manage Token in a fairer way.
