When we talk about ETH L2, we are basically talking about Rollup. Other technical solutions (side chains and state channels have been eliminated), and the much-discussed dispute between OP Rollup and ZK Rollup, has become the mainstream discussion topic now, but in mainstream encryption discussions, the ZK solution will be the final technology of Rollup!

Just recently, a16zcrypto released the latest zkEVM solution Jolt, which is 2 times faster than traditional technical solutions and is simple and efficient.

In addition to the current Jolt, another highly anticipated solution is ProjectZKM incubated by MetisL2, a unique zkMIPS proof architecture with great potential.

Let’s take a closer look at each ZK solution and Metis’ unique ZKM advantages!

1/ zkVM & zkEVM

zkVM refers to zero-knowledge virtual machine, and zkEVM is zero-knowledge ETH virtual machine. The concepts of the two are very similar, both verify the correct execution of the program. The main difference between them is whether the program runs on the chain (zkEVM) or off-chain (zkVM), whether it is written in a smart contract language and supports smart contracts (zkEVM).

However, traditional zkVM performs a lot of tedious calculations in the process of generating proofs, so its performance is poor and it has not yet been widely used.

2/ZKM (@ProjectZKM)

ZKM is building a general-purpose zkVM called zkMIPS, which aims to provide a solution for secure and verifiable computation.

zkMIPS has good potential:
• Good privacy, can prove you own the data without revealing it
• Good capacity footprint, smaller than the original data, can create proofs for large amounts of data
• Verifiable computing enables the use of trustless data in cloud computing, blockchain, and machine learning

3/ ZKM

zkMIPS mechanism:

The zkMIPS proof uses the FRI protocol and has made many optimizations to improve simplicity:
① Divide the program into segments and use parallel proof for each segment
② All segments are the same size, maximizing the efficiency of continuation proof
③Compared with the Jolt solution, the search path is optimized and the cost is reduced
④ Off-chain and on-chain programming languages ​​can be easily compiled into MIPS, and EVM compatibility is wider

The above advantages make ZKM provide a faster, safer and more compatible solution.

4/ Hybrid Rollup

In the ZKM roadmap, the first phase will develop a Hybrid Rollup that is a mixture of Op Rollup and ZK Rollup, combining the advantages of both. This is also one of the killer features of #Metis.

Before we introduce it, let’s use a fast food restaurant as an example to briefly introduce what Rollup is:

In a crowded fast food restaurant, in order to solve the problem of daily checkout congestion, the restaurant introduced a new cash register system that allows all customer orders within a month to be bundled into one transaction.

Bundling all orders into one transaction can significantly improve checkout efficiency, reduce restaurant congestion, and increase table turnover.

5/ Hybrid Rollup

Similarly, the principle of Rollup is to bundle multiple transactions on Ethereum together, then process them outside the Ethereum network, and only merge the final results and transmit them to the chain, thereby effectively reducing congestion.

The two mainstream Rollups are OP and ZK:

• OP packages all the data and processes it off-chain, but there is a waiting period. If no one questions the transaction, it will be uploaded and summarized. The disadvantage is that the time cost is relatively high.

• ZK uses zero-knowledge proof to verify transaction validity, which has low time cost but has difficulty in processing complex transactions.

6/ Hybrid Rollup

It can be seen that OP and ZK have their own advantages and disadvantages, so hybrid Rollup came into being.

The front end of Rollup is similar to OP, but most transactions are verified using ZK, and verified transactions can be submitted directly to L1 without waiting for OP's 7-day fraud challenge. Only transactions that fail verification will enter OP's 7-day fraud challenge stage.

Its advantage is that it retains the original OP architecture while greatly reducing the time cost required for verification, and ensuring security and efficiency.

7/ Hybrid Rollup

Therefore, the overall process of ZKM is:

• When a user sends a transaction, the OP sorter sorts and compresses the data.
• Unchallenged secure data is fed into L1 after zero-knowledge proof by zkMIPS
• Challenged and failed transactions will be deemed invalid


8/ @MetisL2

Hybrid Rollup is still not common in the industry. The team behind the design and implementation of such innovative technical solutions is @MetisL2. ZKM was incubated and founded by the Metis team.

Metis was originally an L2 based on OP Rollup architecture. Thanks to the research and development with ZKM, it has achieved its upgrade from OP Rollup to hybrid Rollup. This is one of the biggest differences and advantages of Metis as the head L2 compared to#ARBand #OP.

9/ @MetisL2

In addition to its excellent hybrid Rollup solution, as a star L2 public chain, another feature of Metis is its excellent decentralized sorter.

Currently, sorters such as#ARBand#OPare relatively centralized, with potential drawbacks of censorship, MEV extraction, and single point of failure.

Metis solves the above problems by establishing a sorter pool.

10/ @MetisL2

There are many sorters in the Metis sorter pool that work together to sort and package transactions. Each sorter is a node, which requires users to elect as a whitelist user and pledge 20,000 $METIS tokens.

The advantages of this model are:
• Greatly improved decentralization
• Greatly improved sorting and packaging efficiency
• At the same time, it can minimize the loss caused by single point failure

Summarize:


Metis is one of the few ETH L2 projects we are optimistic about. The @projectzkm ZK technology solution incubated by @MetisL2 has great innovative advantages and potential. In the current L2 market, the solutions of Metis and ZKM are relatively eye-catching in L2. At the same time, the Metis team also put out $METIS worth 400 million US dollars as an ecological incentive fund, which has also received a lot of attention among the L2s. Therefore, the future prospects of#Metisare immeasurable!