By utilizing ZK-Rollups-based scaling solutions, Layer 2 NFT platforms aim to solve the gas and transaction speed issues for NFT traders. This article compares two of the most popular Layer 2 NFT protocols based on ZK-Rollups, i.e., ZKSea and Immutable X, in the aspects of technology and product experience.
I. What is ZK-Rollups?
Proposed by Ethereum researchers and characterized in that all computing processes are completed off-chain and stored on-chain. The plaintext data in the computing is sent to the on-chain contract in the form of calldata, to reduce the storage cost. At the same time, the correctness of the off-chain computing is guaranteed by the zero-knowledge proof algorithm. With such designs, this solution can greatly increase TPS and reduce the cost of a single transaction. According to the data from L2fee.info, Layer 2 protocol based on Optimistic Rollups technology can reduce the gas fee on the Ethereum mainnet to approximately one-tenth, while based on that, Layer 2 protocol based on ZK-Rollups technology can further reduce the Gas fee by times, possessing better scalability and broader future.
II. About ZKSea
Following a massive rebranding campaign, the L2 Labs Foundation launched ZKSpace, a full-featured Layer 2 protocol leveraging ZK-Rollups technology, including three core products: ZKSwap, ZKSquare, and ZKSea.
ZKSwap is a decentralized exchange protocol based on the Automated Market Maker (AMM) model, which supports users to list any ERC20 token trading pairs and conduct token swaps.
ZKSquare is a low-cost Layer 2 payment protocol, with which users can enjoy real-time settlement Layer 2 payment service by paying a gas fee that is tens of times less than that on the ETH mainnet. It has been widely used in the fields of reward distribution and airdrops.
As an infrastructure that supports Gamefi and Metaverse, ZKSea is the first ZK-Rollups-based platform supporting Layer 1 - Layer 2 NFT mutual transferring, which can greatly reduce the cost of minting and trading NFT on the ETH mainnet. Users can enjoy extremely high flexibility and the composability of ETH ecology when creating NFT on Layer 2 with ultra-low gas fee and transferring NFT from Layer 2 to Layer 1 and backwards. Features like auctions and mystery box sales will also be added in future iterations of ZKSea.
III. About Immutable X
Immutable X is using Starkware's Validium/ZK-Rollups-based zero-knowledge proof system (Immutable X will allow users to choose between Validium-based and ZK-Rollups-based in the future). Validium improves system operation efficiency, but reduces the security of the zero-knowledge proof system at the expense of data availability; while the complete ZK-Rollups post all transaction data on-chain, ensuring the same security as that on Ethereum Layer 1, but the cost is relatively high. The Immutable X NFT trading market adopts order book mode, which means that users can buy NFT on the market only by recharging the funds on Ethereum mainnet into the Layer 2 wallet and have a comparatively nice experience since the transaction speed and cost of simply buying and selling NFT are far lower than those of the Ethereum mainnet.
IV. Immutable X vs. ZKSea
|
Immutable X |
ZKSea |
Notes |
|
|---|---|---|---|
|
Zero - knowledge proof solution |
ZKStark-based, and can be realized in cooperation with StarkWare |
ZKSnark-based |
For ZKStark, it is not needed to initiate trust, while ZKSnark needs it. |
|
For ZKStark, it is not needed to initiate trust, while ZKSnark needs it. |
Validium-based now, may be ZK-Rollups-based later. |
100% ZK-Rollups |
Validium sacrifices data availability to improve system operation efficiency, but reduces zero-knowledge proof system security. The 100% ZK-Rollups solution fully ensures the same security as the ETH mainnet. |
|
L2 transaction speed |
9000 TPS from its official claim. |
In theory, the TPS can be expanded to tens of thousands |
The 9000TPS is currently in doubt, and the TPS in actual use is about dozens |
|
NFT standards Supported |
ERC721 |
ERC721 |
Immutable X claims to support ERC1155 later |
|
Does it have its own NFT market |
Yes |
Yes |
|
|
Token empowerment |
IMX token can be used for Immutable X proposals, transaction fee payment, Staking to obtain rewards, etc. |
ZKS token can be used for 1. PoS, PoG, PoL, PoT and other mining outputs; 2. community governance; 3. platform fee deduction; 4. buyback & destruction schemes, etc. |
ZKSea empowers platform tokens more |
|
Transaction mode |
Order book mode |
Order book mode |
|
|
Transaction fee |
Must be paid with IMX Token |
Support multiple tokens to pay transaction fees, at the user's choice |
|
|
Interaction mode |
API |
APP and web API |
According to the official introduction of Immutable X, they focuses on the API construction of the protocol, and will not carry out too much page development. |
|
NFT issuance mode |
Email to the official platform for cooperative issuance |
Users can independently edit their own homepages, create and issue NFT; introduce well-known IPs through official cooperation |
ZKSea provides users with a low-cost and fast NFT creation tool on Layer 2 |
|
Layer 2 wallet |
Manage accounts through starkex account. Multiple authorizations & signatures are required for Layer 2 account opening and connection to the wallet. |
Self-created user wallet on Layer 2, managing and displaying ERC20 Token and NFT, connecting to Layer 1 wallet to complete public key registration. Users can get a better experience. |
ZKSea provides a complete Layer 2 Token wallet. |
|
Whether to support NFTs issued on Layer 1 |
No |
Support depositing NFTs on Layer 1 to ZKSea for transfers and transactions, as well as the withdrawals to Layer 1. |
ZKSea supports NFT deposit to reduce the gas fee of NFT transactions on Layer 1, and to improve the transaction speed. |
|
Whether NFT withdrawals from Layer 2 to Layer 1 is supported |
If the issuer considers that it will be withdrawn to Layer 1 at the time of NFT issuance, the Immutable X NFT smart contract of Layer 1 must be prepared. |
Yes |
ZKSea stores all NFT issued on Layer 2 in the same Layer 1 smart contract, and the NFT issuer can withdraw the NFT minted on Layer 2 to Layer 1 at any time. |
It is worth noting that:
- At present, the NFTs on the Ethereum mainnet cannot be deposited to Immutable X, and if NFTs on Layer 2 need to be withdrawn to the Ethereum mainnet, the Immutable X NFT smart contract on Layer 1 needs to be prepared before its issuance. The NFT market on Immutable X, in a way, is more like a closed "paradise". By contrast, ZKSea supports all ERC721 standard NFTs to be freely deposited and withdrawn between Layer 1 and Layer 2, directly.
- The NFT transaction fee on Immutable X must be paid in IMX tokens, that is, there is no other choice for users. However, there are more choices on ZKSea, on which users can choose among ETH, USDT, WBTC or ZKS to pay fees.
- Users cannot create their own NFTs directly but have to make an application to Immutable X first. ZKSea, on the other hand, provides a platform and opportunities for anyone to create NFTs on their own at low prices.
- At present, Immutable X adopts the Validium-based solution, in which the data is not posted on-chain, and therefore its security is not as good as the ZK-Rollups solution posting 100% data on-chain, which has been used by ZKSea.
- Immutable X does not provide a complete Layer 2 wallet. Backed by full-featured Layer 2 protocol ZKSpace, ZKSea provides a complete Layer 2 wallet, which allows users to manage ERC20 tokens and NFTs easily.
V. Summary
Blockchain has rapidly grown over the years, with NFTs being an exciting innovation gaining more and more adoption. To provide cheap, fast and cheap minting options to NFT players, product developers have been continuously exploring better scaling solutions with different approaches being taken. This article is intended to let users further understand the characteristics of different Layer 2 NFT products. The ZKSpace team will focus on the research of Layer 2 solutions based on zero-knowledge proof, and continue to walk at the front line of both technology and products, to constantly bring more powerful and meaningful products to NFT enthusiasts.