Study Guide for Blockchain Hybrid Consensus Mechanism

Short Answer Questions

Please briefly describe the main differences between Proof of Work (PoW) and Proof of Stake (PoS).

What existing problems of PoW and PoS does the hybrid consensus mechanism proposed in this patent attempt to solve?

In this hybrid consensus mechanism, what roles do PoW miners and PoS validators play respectively?

What are the characteristics of the "Stable Coin" cryptocurrency mentioned in the patent?

Why is it said that this hybrid consensus mechanism can provide the necessary randomness and timeliness for the PoS system?

What is a "validator committee" and how is it generated?

What does "epoch" refer to in this hybrid consensus mechanism?

What is the "CER" mentioned in the patent and what is its role?

How does this hybrid consensus mechanism ensure that the system can continue to operate even if some nodes fail or act maliciously?

Compared with the traditional PoW mechanism, what are the advantages of this hybrid consensus mechanism in terms of energy consumption?

Answers to short-answer questions

PoW relies on computing power competition to solve puzzles to verify transactions and generate new blocks, while PoS selects validators to verify and generate blocks based on the number of tokens staked by the node. PoW consumes a lot of energy, while PoS has problems such as the rich getting richer and attacks with no stakes.

This mechanism attempts to solve the problems of high energy consumption of PoW and lack of randomness and timeliness of PoS, which makes it vulnerable to attacks. It combines the advantages of the two mechanisms, using PoW to provide randomness and timeliness for PoS, while using PoS to maintain the ledger and bookkeeping.

PoW miners are responsible for solving puzzles, providing random number seeds for the PoS system, and receiving token rewards. PoS validators form committees based on random number seeds, responsible for verifying transactions, generating blocks, and maintaining ledgers.

Stable Coin is a stable cryptocurrency designed to solve the problem of large price fluctuations of existing cryptocurrencies. It links the production cost of tokens to the arbitrage behavior of miners, and uses global electricity prices as an anchor to achieve a long-term stable market equilibrium price.

It takes a certain amount of time for PoW miners to solve the puzzle, which provides an unforgeable timestamp for the PoS system. At the same time, the solution to each puzzle is also random, which ensures the randomness of the selection of the PoS validator committee.

The validator committee is composed of a part of the PoS nodes and is responsible for verifying transactions and generating new blocks. The members of the committee are randomly selected from the candidate node pool based on the random number seed provided by the PoW miners.

"Epoch" refers to a period of time when the members of the validator committee remain unchanged. In an epoch, committee members take turns to serve as block proposers and jointly verify and sign new blocks.

CER (Committee Election Relay) is a PoW chain independent of the main chain, which is used to generate random number seeds and trigger the election of the PoS validator committee.

This mechanism adopts the Byzantine Fault Tolerance (BFT) consensus mechanism. Even if one-third of the nodes fail or act maliciously, as long as the remaining nodes exceed two-thirds, the system can operate normally, ensuring the robustness of the system.

The traditional PoW mechanism requires all miners to continuously compete for computing power, consuming a lot of energy. In this hybrid consensus mechanism, PoW miners only compete for computing power when a new validator committee needs to be generated, which greatly reduces energy consumption.

Essay Question

Compare and contrast the PoW and PoS consensus mechanisms in detail, and explain why the hybrid consensus mechanism is a solution that combines the advantages of both.

Explain how the hybrid consensus mechanism proposed in the patent solves the "no-stakes attack" and "long-range attack" problems existing in the traditional PoS system.

The patent mentions that the "Stable Coin" cryptocurrency is intended to be a stable measure of value. How feasible and meaningful do you think this stability is in the real world?

The patent describes a hybrid consensus mechanism based on PoW and PoS. Can you propose other feasible hybrid consensus mechanism design ideas?

Discuss the potential challenges and limitations of the hybrid consensus mechanism, such as in terms of security, scalability, and decentralization.

Key Glossary

Term DefinitionsBlockchainA distributed ledger technology that stores data in blocks, each of which contains the hash value of the previous block, forming an immutable chain structure. Proof of Work (PoW)A consensus mechanism that selects the creator of a block by calculating a difficult problem and obtains a reward, such as Bitcoin. Proof of Stake (PoS)A consensus mechanism that selects the creator of a block based on the number of tokens staked by the node and obtains a reward, such as Ethereum 2.0. Hybrid consensus mechanisms combine the advantages of both PoW and PoS mechanisms, such as the mechanism proposed in this patent. Miners are nodes that calculate difficult problems and obtain rewards in the PoW mechanism. Validators are nodes that verify transactions and generate blocks in the PoS mechanism. Validator CommitteeA committee composed of a portion of PoS validators that is responsible for jointly maintaining the security of the blockchain. Random number seeds are used to generate the initial value of random numbers, which are provided by PoW miners in this patent. EpochA period of time during which the members of the validator committee remain unchanged. CER (Committee Election Relay) is a PoW chain independent of the main chain, used to generate random number seeds to trigger the election of the PoS validator committee. Stable Coin is a stable cryptocurrency proposed in this patent, which aims to solve the problem of large price fluctuations of existing cryptocurrencies.