Produced by: Vernacular Blockchain (ID: hellobtc); Author: Five Fireball Leader

The hottest "technology" event in the circle recently is undoubtedly the launch of Arbitrum.

There is no other reason. Last year, Vitalik has decided that Rollup will be the main expansion method of ETH. In the future, in the 2.0 sharding era, it will also undertake the historical task of ETH's "global settlement layer" together with sharding. After setting the tone, LRC (Loopring Protocol) is the first project to implement the Rollup solution, but LRC is essentially just an application, not a general-purpose Rollup solution.

Arbitrum, which has just launched its mainnet, is, strictly speaking, the first "universal Rollup Layer 2 expansion solution" that has launched its mainnet in history(OP launched the test network earlier, but the main network will be in July and August).

In the past few days, I have seen people asking in many communities: "Which one is better, Arbitrum or Matic? Aren't they both Layer 2? Which one is better, Arbitrum, Optimism and Zk-Sync behind it? Aren't they both Rollup?"

but aboutLayer2There are already a lot of introductions and comparisons of the solution, so this article intends to completely put aside the technology and completely talk about the differences between these few. The advantage is that even friends who have just entered the circle should understand it to some extent.

The disadvantage is that the scene simulation inside is not completely accurate from a technical point of view. It is only needed for "vernacular" explanations. Friends who want to really understand the details of several Rollup solutions should read the explanation article on technical comparison.

We will introduce 4 differences, namely the difference between Rollup and sidechain; the difference between OP and ZK; the difference between Optimism and Arbitrum in OP; the difference between Zk-Rollup and Validum in ZK.

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01 The difference between Rollup and side chain

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What is the difference between Layer1 (specifically referring to ETH) and sidechain Layer2 (specifically referring to Rollup)?

Layer1 You are extremely assured of the exchange that takes place on ETH, that is, the financial escort initiated within NATO. Because you feel safe, after all you are paying the military, which is the most powerful armed force in the world and has an excellent international reputation.

The exchange on the side chain-Matic is equivalent to that your financial escort did not take place in NATO, but in India, and the Indian army was responsible for the escort.

If your starting point and ending point are both in India, then the entire Indian army escort has nothing to do with NATO. If your starting point is in India and your end point is in NATO territory, the Indian army will be responsible for the escort, and then the convoy will be handed over to the NATO army to continue the escort when it reaches the junction of India and NATO territories.

Therefore, compared with Layer 1 (pure NATO territory), side chains differ in the following points (from a security perspective):

1. The Indian army is not as strong as NATO. In theory, there is a risk of domestic terrorists hijacking your convoy.

2. Even if there is no hijacking by terrorists, there is a possibility that the Indian army may secretly confiscate part of the money you have escorted.

You may want to escort 10 million from India to the NATO border, but when the Indian army and the NATO army are handed over, there are only 5 million left in the car. The NATO army will only believe the amount of money and the documents of the Indian army. The 5 million of the Indian army was embezzled by the escorted Indian army, and there is no doubt that the documents were also faked.

This is why it is said that the security of the side chain is lower than that of Layer 1, because the nodes (army) are independently owned by the side chain and have nothing to do with the main chain.

Other high-speed chains, such as Near and Ftm, are connected to ETH through bridges. You can think of these chains as South Korea, Japan and other countries that have exchanges or trade with NATO. The security of each country is different, depending on the military. strength, and reputation.

So what is Rollup?

Rollup is equivalent to - if you regard Arbitrum as the African continent, then on this land, the armed escorts are the direct troops of the NATO army, or the armed robots directly and remotely controlled by the NATO army.

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02 The difference between Optimistic Rollup and ZK Rollup

OP: Optimistic Rollup - Optimistic Rollup
Zk : ZK Rollup - Zero Knowledge Proof Rollup

Where is the difference? With the above scene foreshadowing, the difference between these two is actually not difficult to understand: OP is a direct-line army; ZK is an armed robot.

How do you understand it?

OP- When you are in financial escort on the African continent, because the equipment of the direct troops comes from NATO, with strong firepower, you don't worry about terrorists or anything. The only problem is,When your escort is about to enter NATO territory, the handover of direct troops and NATO troops begins, and your funds need to be frozen for a few days。

Because the direct-line troops in charge of escorting have the possibility of being blinded by money and being blackened, it is not impossible in theory that the Indian army deducts 5 million from you for 10 million. After all, it is only direct-line. Just an optimistic acquiescence that they have as good a reputation as NATO troops.

Assuming that the direct descendants of the French army are in charge of the escort, then the direct descendants of the British army can challenge during the freezing period, questioning the French direct descendants for "making trouble" during the escort. Due to the various documents and financial certificates at the beginning of the escort, the direct line troops had to fax to the NATO local army, and in the direct line army, there was a NATO local war reporter who took photos and recorded everything that happened on the road. Therefore, the NATO troops It is entirely possible to prove through the court trial whether the French direct army did something wrong during the escort.

If it is confirmed that it is indeed "guilty", then the French direct line will be fined or "deducted from military pay", and the time when the funds are frozen is used for "challenge" and "court trial"。

ZK-Armed robots directly and remotely controlled by the NATO army have powerful firepower and at the same time, there is no possibility of "doing things". After all, robots don't have independent thinking, and they don't think of greedy for your 5 million. Their integrity is essentially the same as that of the NATO army that controls them.

Therefore, when the escort enters NATO territory from Africa, there is no freezing time for your funds. After the handover ceremony is completed in a few minutes, the robot can be replaced by a human army to continue the escort.

that's whyThe reason why V God said to look at OP in the short term and ZK in the long termfirst level title

03 The difference between Optimism and Arbitrum in OP

Both Optimism and Arbitrum use direct-line troops. The most intuitive difference is that when the escort enters NATO territory, and other direct-line troops question the escort and challenge it, the two sides handle the "court trial" process differently. .

The OP is to let the NATO army use a time machine to go back to the moment when the escort started, and the NATO army will replace the direct line troops to run the entire escort process again, and then compare.The advantage is that it can be done once, but the disadvantage is that the time machine is used for a long time and the cost is relatively high。

Arbitrum first watched the video footage of war correspondents to find the problematic section, and then the NATO army took a time machine to go back to the problematic point in time to find out what went wrong.

The advantage is that the cost is lower, because the time machine is only opened for a while, and the disadvantage is that the overall time spent is longer than that of using the time machine directly at the beginning.Because it takes time to watch the video to find where the divergence point is.。

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04 The difference between MatterLabs and Starkware in Zk

Originally, there were some differences between the two. Matter Labs used ZK-Rollup, and Starkware used Validium, which is similar to Zk-Rollup.

so

soNow the difference is mostly in the minutiae. The zero-knowledge proof used by MatterLabs' Zk-Sync is called Zk-SNARKs - Concise Non-Interactive Zero-Knowledge Proof; the zero-knowledge proof used by Starware is called Zk-Starks - Concise and Transparent Zero-Knowledge Proof.

If they are different, they can be understood as,One is an armed robot controlled by the IOS system, and the other is an armed robot controlled by the Android system。

Instead, what we can talk about here is the difference between Zk-Rollup and Validium. The difference is simple, ZK-Rollup's data is on-chain, while Validium's data is off-chain.

What does it mean to put it in our scene, it is actually very simple。

Zk-Rollup- The war reporters of the NATO army followed the armed robots all the way, and everything on the road was recorded and sent to the NATO headquarters. It is conceivable that this method is safer, but the cost is relatively high. You need to shoot one more reporter, and you have to upload data all the way.

Validium-There are no team reporters, only robots, and no one records what happens on the road. what will happen Robots have powerful firepower, and terrorists are not worried. But what if some super-powerful hacker hacks into the robot without anyone noticing and takes away the user's funds, but what if the controller of the robot knows nothing?

Because there are no reporters and no videos, users can only suffer from being dumb. Therefore, the security of Validium is weaker than that of Zk-Rollup, but the benefits are also obvious. There is no need to photograph reporters to follow, and there is no need to upload data all the way, and the cost is much lower. This is why the performance of Validuim is much higher than that of Zk-Rollup.

After all, you can't have both a bear's paw and a fish.

Although it is not rigorous and accurate, I hope this article can at least give you a general understanding of the "grievances and grievances" of sidechains, Rollup, OP family and Zk family.