Layer 2 battle: Optimism in the short term, zkSync in the long term?

2022-11-21 18:00

Read this article in 11 Minutes

The world of blockchain has never been "technical only".

Original author: Lao Bai

Today, let’s talk about Layer 2’s dispute between OP and ZK

Short-term OP, long-term ZK?

This sentence is said by God V, so it is considered by many people to be the "golden rule", but the actual situation is much more complicated.

The common kind of comparison has already been said badly on the Internet-that is, OP is based on games < ZK is based on mathematics; OP1 has a two-week withdrawal period< ZK withdrawal period is only Minutes to hours; OP's EVM compatibility is better > ZK compatibility is a long way off...

The above is no longer nonsense. V God’s long-term and short-term remarks are generally based on the above three fundamentals.

However Gaming VS Mathematics - users don't experience any difference at all, and don't care at all; two week withdrawal period VS minutes or hours - these differences There are bridges all smoothed out; EVM compatibility - OP is indeed better now, but this will eventually be smoothed out as ZK slowly develops.

So say something different.

One. The first is performance

A common saying is ZK The TPS of the system is higher than that of the OP system. The main reason for this is that the compression ratio of ZK is higher than that of OP. In other words, when the compressed transaction data is submitted to L1, ZK can submit it at the same time because of the higher compression ratio. More transactions than OP, converted into TPS will naturally be higher.

However, this statement ignores the huge overhead and time-consuming that ZK needs to generate proofs.

Therefore, the performance of OP VS ZK is more likely to be a style that alternately rises, and ultimately leads to the same goal - the following is a brain hole

1. ZK just launched - OP TPS is high, because the cost and time-consuming proved by ZK far exceeds the advantages brought by the compression ratio

2. The Prover architecture of the ZK series is relatively mature - ZK TPS is high, ZK machines such as FPGA or ASIC have come out, ZK proves that the cost and time consumption have dropped significantly, and the compression ratio has advantages It began to appear

3. Pro-Danksharding is online- OP and ZK TPS are almost the same, because L1 does not use Call Data, A Blob with much larger space and lower cost is used as DA, so the advantage of compression ratio at that time is far less obvious than in the current Call Data era. The small advantage of the compression ratio and the small disadvantage of the ZK proof basically offset each other, and the theoretical TPS limit of OP and ZK is basically limited by the hardware processing capability of the Sequencer.

Secondly, the actual advantage in the ZK market

Password Learning > game, the withdrawal period is much smaller than that of OP is ZK's technical advantage, but not necessarily in the market, the world of blockchain has never been "technical only". Just like now that ETH has changed from POW to POS, there are still many OGs and technical experts in the currency circle who are tirelessly publishing articles arguing that POW is better than POS, and you have to admit that many of their arguments are really reasonable, even correct.

But it’s not important, the market thinks that POS is the future of the new public chain (excluding BTC), what can you do?

So where is the actual advantage in the ZK market? I can think of two for the time being

1. ZK, as the current blockchain technology "distinguished learning", may bring Fire an industrial chain, just like POW brought fire to mining machines (from CPU to GPU to FPGA to ASIC), mining pools, mining farms, computing power derivatives and a series of upstream and downstream industrial chains, ZK may also go from proof to verification Bring out a POW-like, hardware-based industrial chain

2. ZK can play more tricks - such as realizing privacy Function (Aztec), such as the article "What kind of layer3 is meaningful? "- It mentioned a scene where Arb's native Token "cross-chain" to Optimism (Wrap mode)

Because it depends on ETH L1 at the same time, the Optimism side The Wrap contract can completely bypass the current "unsafe" bridges by reading the Merkle certificate of the deposit contract receipt uploaded to L1 by Arb, but in theory, OP-type L2 deposits should wait for a fraudulent window period (7 days) is considered safe in the past, so it is difficult to do this. If you switch to ZK, this scene will be fine

3. Finally, let’s talk about the ending of ZK and OP

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You feel that ZK-sync, Scroll, etc. have already started the Alpha test network, and you think ZK will be available soon? Too naive, ZK still has a long way to go. For example, the official ZKEVM circuit code of the Ethereum Foundation has more than 30,000 lines. We cannot fully rely on the security brought by the ZK system”

Of course, although the OP is leading, but the road has not yet come to an end. For example, due to the change of the OVM architecture in Optimisim, the core fraud proof function of the OP has not yet been launched, and many people do not know it. So what might the endgame look like? V God also gave a mixed mode solution, which I personally think is quite reliable, maybe it will be like this in a few years What's it like? All in this thread

Before zkEVM matures, OP is the main force and ZK is the supplementary

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1. Post block

2. Wait for 24 hours

3. If there is no fraud challenge during the period, release ZKP, Finalize block

Else (challenged), introduce Governance, cut through 2of3 model

Determine the final result

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After zkEVM matures, ZK will be the main and OP will be the assistant

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1. Post block

2. Release ZKP regularly

3. If ZKP is released normally during the specified period, Finalize

Else (ZKP is not released normally during the period, whether Prover hangs or a bug occurs), the system switches to the Optimistic mechanism until the ZK mechanism recovers.