Motivation

To bridge the gap between traditional web users and the growing world of Web3, we propose a non-transferable gas token named SoulQKC, where QKC is the native gas token of a Rollup. The concept revolves around facilitating Web2 users' entry into Web3 by airdropping them with QKC. This token will enable users to pay for transaction gas fees without the immediate selling pressure of the airdropped token. This initiative is particularly aimed at those new to Web3, providing a seamless transition without the upfront cost of acquiring a gas token.

How It Works (Using OP Stack as a Case Study)

• Technical Implementation: SoulQKC is managed through an ERC20 contract with a twist: anyone can **mint** new tokens by deposit QKC. To maintain its non-transferable nature, all attempts to use ERC20's transfer, transferFrom, or approve methods will result in failure.
• Wallet Compatibility: The transaction format remains consistent with existing Rollup ones. Users can transact using ETH wallets without the need for additional ones (e.g., AA wallets), ensuring a smooth user experience.
• Gas Fee Process: For an L2 transaction, the fee will first be deducted from the user's SoulQKC balance. If the balance is insufficient, the system will then draw from the user's QKC balance. To account for the additional processing cost of SoulQKC, the base gas cost may be slightly higher than traditional transactions, likely from 21,000 to 21,000+2,100+5,000=28,100 gas. Note that the token transferred in msg.value will be always from the user balance, preventing transferability of SoulQKC token.

Potential Challenges

• Sequencer Incentives: The sequencer will receive the gas fee in QKC as used_price * gas_price.
• Risk of DoS Attacks: The introduction of a "free" transaction token like SoulETH could potentially incur denial-of-service (DoS) type attacks. Mitigation strategies include limiting the initial airdrop quantity to support a finite number of transactions, coupled with a mechanism to replenish SoulQKC for users with verified on-chain behaviors.
• Sybil Attack Prevention: Airdrops are susceptible to exploitation through Sybil attacks. We will implement established best practices of airdrops to identify and mitigate such threats effectively.

Comparison with SoulETH

Concluding Remarks

This proposal outlines a novel approach to lowering the entry barrier into Web3, leveraging SoulQKC as a transitional gas token for Web2 users. By addressing the outlined challenges and focusing on user onboarding experience, we believe SoulQKC can significantly contribute to the wider adoption of Web3.