The New King of technology?

Conclusion: Isomorphic multi-chain technology will be the most important one
Technical importance

As a pioneer of blockchain technology, Bitcoin has an unbreakable status.

Ethereum achieved a major technological breakthrough through smart contracts and became the representative of the second generation.

EOS has achieved a significant increase in TPS through super nodes, occupying the second throne of the smart contract public chain.

Polkadot and Cosmos are sought after as inter-chain projects.

Many projects are still on the road of technological reform.

Why are we still talking about technology?

The existing phenomenon is one application one chain. The computing power and users cannot be shared, and the credibility is low (island problem).
Most public chain performance is subject to the performance bottleneck of a single node.
The theoretical upper limit of the TPS performance of ordinary computer nodes is about 7,000 TPS, which is difficult to meet the demand.

Alipay's payment performance on 11/11 and other event days can reach hundreds of thousands of TPS.
With the promotion of smart contracts, more and more applications will use smart contracts, and the performance requirements of the public chain will increase again.
CryptoKitties cause congestion of the entire Ethereum network.
An airdrop project, EIDOS, caused serious congestion on the EOS network.

How to share computing power, credibility, users? What it needs is a scalable, ultra-high performance public chain to be able to solve it.

Only when such a public chain comes out, the applications can be implemented on a large scale, thereby carrying a trillion-level market.

Comparison of technical solutions
1. Optimization direction: single-chain upgrade, multi-chain parallel, DAG.
Single-chain upgrade: By modifying the consensus, increasing the block size and changing the generation speed, thereby improving performance, such as BTC-> BCH, BTC-> LTC
Multi-chain parallelism: side-chain technology, lightning network, heterogeneous inter-chain, homogeneous multi-chain

DAG: Through directed acyclic graphs, lock transactions directly through transactions (the common way is to lock the block through block), not subject to the block size

Most projects are now useful for several technologies, not limited to a single technology.

2. Technical comparison (multi-chain solution):
Sidechain technology:
The typical representative is the sharding technology of Ethereum. By handing transactions to different shards, different shards can process transactions at the same time, thereby achieving multi-threaded processing.

Its problem: For example, user u1 purchases token tn through a contract, and user u2 also purchases token tn through a contract. However, the total amount of token tn is limited. In the same shard, it is easy to find the problem and reject the block. If u2 transactions are in different shards, what should be done?

Some people say that this is simple and can be solved by sharing information. What about more complicated problems? For example, if there is a lottery contract, the winner will receive half of the prize pool, then if two people win the prize at the same time, the transaction bonus will be much worse ( the first transaction will get 50% reward , and the second transaction will get 25% reward )
There is a more complicated problem. The contract triggers the contract. There is no conflict in the upper contract, but the contract after the trigger conflicts.

This is a big challenge that Ethereum sharding technology needs to face, and it may also be the problem that its technology has been delayed.

Some projects can create independent side chains, which are classified as heterogeneous inter-chain technologies.

Lightning Network:
Its transaction speed, transaction fees, and scalability are all very good, but its channel is complicated, there are not enough people to use, and there is a suspicion of channel centralization

Heterogeneous inter-chain:
As mentioned earlier, due to the existing performance problems, most applications are one application one chain, and the chain and the chain exist independently and are not related, resulting in the "island problem."

Computing power, users, and credibility cannot be shared, which is equivalent to starting over. At the same time, if it is a POW mechanism, it is also easy to be attacked by the mining pool (a large number of miners influx, resulting in a sharp increase in computing power and then leaving the field, which will cause new blocks to be difficult to dig due to insufficient computing power).

The inter-chain solution is to solve the intercommunication problem of different blockchains. Through the bridge between the two chains, they can communicate with each other.

Existing problems:
It can't solve the problem of inconsistent computing power; it can only achieve the interaction between blockchains through institutional solutions (requires a supervisor); this technology cannot solve the problem of uneven computing power and different credibility.

In addition, the rate fluctuation problem of different blockchains, such as BTC to BCH, was transferred at 1:30. It was submitted here, but it has not been transferred to me there, but the rate has become 1:35. Should we admit this deal? At what rate? Who bears the loss?

Another problem: BCH was transferred to me after the transaction was completed, but suddenly the mining pool used a lot of computing power to make double spending, and the BCH of the other party's account was not enough to pay me the fee, then I would lose those BCH forever.

Another question: If the amount of the transfer is sufficient, the validator / collator disappears collectively, if I transfer out BTC, but do not transfer BCH to me, what should I do?

Representatives of this scheme are Polkadot and Cosmos

Therefore, heterogeneous inter-chain is only suitable for small transactions, and cannot be guaranteed to be 100% reliable

Isomorphic multi-chain:
What is isomorphic multi-chain?

A blockchain system is composed of multiple chains, all of which are part of the system, with the same virtual currency, consensus, shared computing power, and users. It is equivalent to a variant of the side chain.

Due to the same consensus and currency, different chains within the system can transfer money freely.

The entire system is similar to UnionPay, each chain is similar to a bank, and the wallet address is a universal card number.

All banks are connected to UnionPay in accordance with the regulations (consensus) of the central bank. Users can transfer money between different banks, and they can purchase any bank products (in-chain transfer or execution of contracts).

In order to avoid fraud within the chain, through the hash lock between adjacent chains (the ordinary blockchain only has hash locks for the front and back blocks), the existence of counterfeit blocks is completely avoided.

Smart contracts are equivalent to the cooperation activities between banks and merchants. A smart contract can be deployed on different chains to serve users on different chains.

When there is a lot of transaction volume, as long as a new chain is created, system performance can be improved and users can be diverted.

Advantages: to achieve high scalability of the entire system.

Disadvantages: An account has money on each chain, resulting in the dispersion of funds.

The representative of this scheme is the GOVM blockchain. It is the best solution now.
GOVM: https://bitcointalk.org/index.php?topic=5230875.0