ZKsync, praised by Vitalik, may really be underestimated.

From being universally criticized to becoming a hot commodity, ZK has ushered in a dawn. The ZKsync Atlas upgrade achieved 1 second ZK finality, bridging L1 and L2. (Background: ZKSync was hacked “the attacker minted 100 million zk tokens”! The hacker's actions led to emergency delistings on exchanges such as Bithumb) (Context: After the ZKsync airdrop, income evaporated by 99%, $ZK plummeted 60% within two months, is L2 really hopeless?) Vitalik quoted ZKsync founder's tweet regarding the ZKsync Atlas upgrade on November 1 and praised that ZKsync has done a lot of “underestimated but valuable work for the Ethereum ecosystem.” The market quickly reacted to Vitalik's words, with ZK prices soaring over 2.5 times during the weekend, and tokens in the ZK ecosystem, including ALT (AltLayer), STRK (Starknet), SCR (Scroll), MINA (Mina), all saw substantial increases. After understanding the ZKsync Altas upgrade, we realized that what ZKsync has done may indeed be underestimated. Fast, small but expensive ZKP The Ethereum Foundation has been promoting ZKP (zero-knowledge proof) from early on, which essentially aims to solve the problems of slow verification speed and large amounts of verification data. ZKP is fundamentally a mathematical probability problem. To illustrate its principle with a somewhat inaccurate example: suppose someone claims to have solved the “four color theorem,” how can we determine that this person indeed solved it without fully disclosing their solution? The solution of zero-knowledge proof is to select certain parts of the entire graph and prove that there are no two adjacent areas with the same color, and when the number of selected parts reaches a certain value, it can be proven that this person has a 99.99…% probability of having solved the four color theorem. At this point, we have achieved a proof of “indeed solved the four color theorem” without understanding the full picture. This is what everyone often hears about, “proving something has indeed been done without understanding how it was done,” which is zero-knowledge proof. As for why ZKP is vigorously promoted in the Ethereum ecosystem, it is because the theoretical speed limit of ZKP is far faster than proof per transaction, and the generated proof itself has a very small amount of data. The speed is fast because ZKP does not need to understand the full picture, only to conduct challenges. For example, to verify an Ethereum block, the current method is for each node to verify whether each transaction's execution address has sufficient balance and other basic issues, but if only one node verifies each transaction through ZKP, it can then generate a “proof,” and other nodes only need to verify that the “proof” itself is reliable. More importantly, the amount of data for this “proof” itself is very small, so the speed of its transmission and verification is extremely fast, and at the same time, the cost of storing data is lower. As for why this all-advantage technology is not widely applied, it's because it's too expensive. Although ZKP does not require reproducing all processes, the challenges themselves consume a lot of computing power. If one were to crazily stack GPUs like in an AI arms race, faster speeds could be achieved, but not everyone can bear such costs. However, if the required computing power and the time to generate proofs under low computing power can be reduced to a certain extent through algorithmic and engineering innovations, achieving a balance between “price increase driven by technological innovations introducing more applications” and “the cost of purchasing GPUs for building nodes” would be achievable. Therefore, many ZK concept projects or open-source developers in the Ethereum ecosystem focus on combining ZKP with Ethereum mainly on: generating ZK proofs at a lower cost and faster speed under low cost. Recently, the Brevis team achieved an average of 6.9 seconds to prove an Ethereum block with only half the cost of the SP1 Hypercube solution (64 RTX 5090 GPUs), which is why the Ethereum community collectively praises it. Although GPU costs still exceed $100,000, the proof speed has now dropped to a level comparable to the current Ethereum without ZKP, and the next task for everyone is to reduce costs. The Atlas upgrade achieved 1 second of ZK finality Perhaps many people do not know that the open-source zkVM ZKsync Airbender launched by ZKsync is the fastest zkVM verification speed with a single GPU. According to Ethproofs data, using a single 4090, ZKsync Airbender has an average verification time of 51 seconds, costing less than a cent, both being the best performance in zkVM. According to data provided by ZKsync itself, excluding recursion, Airbender uses a single H100 and ZKsync OS storage model to verify the Ethereum mainnet with an average time of 17 seconds. Even considering recursion, the total average time is only about 35 seconds, ZKsync believes this is much better than needing dozens of GPUs to achieve under 12 seconds in proof. However, since currently there are only data showing an average of 22.2 seconds with two GPUs, the actual quality has not been concluded. And all of this is not solely the credit of Airbender; algorithm and engineering optimization are just one part, and the deep integration with the ZKsync tech stack is the key to maximizing the effect. More importantly, it indicates that achieving instant proof for the Ethereum mainnet with a single GPU is possible. At the end of June, ZKsync launched Airbender, and on the second to last day of the National Day holiday, the Atlas upgrade went live. This upgrade, which integrated Airbender, significantly improved ZKsync's throughput, confirmation speed, and cost. In terms of throughput, ZKsync has conducted engineering optimizations on its sequencer: minimizing consumption caused by synchronous generation through independent asynchronous components; separating the state required for virtual machines, the state required for APIs, and the state needed to generate zero-knowledge proofs or verify zero-knowledge proofs at the L1 layer, thus reducing unnecessary overhead for components. After ZKsync's real-world testing, the TPS for high-frequency price updates, stablecoin transfers in payment scenarios, and native ETH transfers reached 23k, 15k, and 43k respectively. Another significant qualitative change comes from Airbender, which helps ZKsync achieve 1-second block confirmations and a cost of $0.0001 per transaction. Unlike verifying mainnet blocks, ZKsync only verifies the validity of state transitions, so the computational load is much smaller than that of verifying mainnet blocks. Although transactions that achieve ZK finality still need to be verified on the mainnet to ultimately achieve L1 finality, having ZK verification indicates the validity of the transaction, while L1 finality is more like a guarantee of procedural nature. In other words, transactions executed on ZKsync only require ZKP verification to be fully confirmed as valid, coupled with the significantly reduced cost, ZKsync has realized, in their own words, the applications that only Airbender can bring…