Do you know the blockchain chain 25 | How deep is the side chain & cross chain water? You still have this 6-point equipment!

Hello everyone, welcome to the ignorant blockchain. I don’t rely on the fat value of the talented person. After the last two sidechains and cross-chain topics, we received the anti-quality feedback from the netizens. (suspect), today we will talk about N big questions about cross-chain & sidechain !

1. The birth and development of cross-chain & sidechain?

Bitcoin came out in 2009. For a long time, everyone's attention has remained on Bitcoin. In 2012 , Ripple released the Interledger Protocol (ILP) , a cross- account interoperability agreement , through third-party notarization. The human approach has realized the cross-book transfer, and the cross-book interoperability scheme was first proposed in the blockchain field. What needs to be noted here is that Ripple 's cross-chain is a cross-chain in a broad sense, because it contains a centralized bank account and other forms. As it is said to be the interledger protocol, not the interchain protocol.

In 2014 , the BlockStream team , founded by the Bitcoin core developer group, first proposed the Pegged Sidechains solution, introducing a two -way peg sidechain to enable cross-chain asset transfer. .

In 2015 , Blockstream once again proposed the Bitning Lightning Network solution, which uses a Hashed Timelock mechanism to open a new era of payment under the Layer 2 network chain.

In 2016 , Ethereum eco company Consensys released the BTCRelay solution, which implemented a one-way cross-link connection from Bitcoin to Ethereum based on the relay solution. In the same year, Vitalik Buterin 's " Chain Interoperability " made a comprehensive and in-depth analysis of blockchain interoperability issues, and many of the current cross-chain classifications on the market are based on this article by Vitalik .

In 2017 , Polkadot and Cosmos first proposed a solution for building a cross-chain network infrastructure platform, hoping to achieve the block web form.

2. Is the lightning network a side chain ?

No! First, the cross-chain technology used by Lightning Network is “hash lock”, and the cross-chain technology used by sidechain is a side chain protocol. The classification between the two is parallel and not affiliation. Why is it so specific? We have already said it in the previous episode, and we will not repeat it here. In addition, the side chain protocol is linked to the chain and chain, while the lightning network is a two-tier network solution, which belongs to the chain payment, off-chain ! Although from a functional point of view, there are some similarities, but they are not in the same category ~

3. Does the presence of side chains reduce the importance of the main chain?

Emmmm, I ask you a question, will the appearance of WeChat reduce the importance of Tencent? If so, why does the pony still have to do WeChat? Just help you here, give you a look, you can experience it yourself!

4. What if the two chains are interconnected and one chain is forked? Will it lead to double flowers?

Let us give an example, if chain A has completed a cross-chain transaction from chain A to chain B , as shown below:


Then chain A was split by hacking. The previous cross-chain transaction is no longer on the longest chain of chain A. Then the previously transferred account can initiate a double-flower attack and send a cross to chain B again. Chain trading, so that chain B will release the corresponding token again, which causes a transaction of chain A to achieve two releases on chain B, resulting in double flowers.


Although we say that we will wait for a period of time for each transaction, but the transaction of the bitcoin lamp blockchain does not have a final state, the extension of the confirmation time can only be said to reduce the possibility of being double-flowered, and cannot completely rule out this. Possibility, so it's best to prepare relevant remedies when doing cross-chain design. We can follow this idea and make an idea about the plan:

The previously confirmed cross-chain transaction has been invalidated due to chain A reconfiguration. For such a failed cross-chain transaction, the failure of the cross-chain transaction is first detected, and the related assets of chain B are frozen, so that subsequent transactions are There will be no problems, and there are no specific technical implementation plans for the project.

5. I haven’t made it out for a long time across the chain. Is it a pseudo-demand?

This answer is naturally negative. When the Internet just came out, everyone played very well in their own stand-alone world. When you play the little bully at home, you are also happy. You will question the future. Do you really need to eat chickens on the internet and strangers around the world? Now you have such doubts, you can only say that the time is not yet!

In addition, the cross-chain has also made a lot of progress in the past few years. We also introduced its development process at the beginning. It has been in the process of groping forward, and everyone continues to look forward to it!

6. How to achieve multi-chain interconnection, how to form the blockchain World Wide Web?

One is the direct interconnection between the two chains. This situation often occurs when the new chain wants to interconnect with the existing chain, and there is often no uniform underlying protocol support between them. In this case, the four chains need to be between Two link interconnections can be established to establish two link paths, and the paths between the two must be customized. Although this method is not scalable, it can guarantee better security and independence. Once an attack occurs, it is difficult to affect the entire network. In the early years, the scheme that wanted to connect with Bitcoin basically belonged to this kind, such as BTC-Relay/RSK, etc. Each path may need to be customized.


The other is to establish a third-party cross-chain platform, in which third-party platforms often develop a common protocol, and all other chains use this set of protocols together, so to achieve the interconnection between the two, only need to pass this The platform is fine. However, the cross-chain platform will become a key point in the entire cross-chain network. Once the cross-chain platform is attacked, the entire cross-chain network will be paralyzed. Typical examples of such a scheme include Cosmos and Polkadot.


From the launch time, the cross-chain project started mainly in the past three years, and showed a trend of increasing year by year. In 2017, the number of cross-chain projects reached a peak. In 2018, the overall market was relatively sluggish, and there were relatively few new cross-chain projects. At present, there are not many platform-type projects that are specialized in cross-chaining, and the overall is in the exploration stage. The main reason is that the infrastructure is not strong enough, and natural demand will not keep up.

In the end we applied a William Gibson old saying: The future is already here – it's just not evenly distributed (the future has come, but it is not yet popular)!