What Is a Permit Signature? How DeFi Enables Gasless Token…
By Tobi Opeyemi Amure
AI summary of the source article
Permit signatures allow cryptocurrency holders to authorize token spending off-chain without submitting a separate on-chain approval transaction. Standards like EIP-2612 and Uniswap Permit2 combine token approvals and execution into a single transaction.
Why it matters
This approach reduces the number of wallet interactions and can lower the overall gas expenditure associated with separate approval and execution transactions.
Key facts
- Ethereum introduced signature-based approvals via EIP-2612, which uses the EIP-712 typed-data signing standard.
- Permit signatures utilize a nonce, a timestamp deadline, and a spending allowance to manage and protect authorizations.
- Uniswap Permit2 extends signature-based approvals to tokens lacking native EIP-2612 support via AllowanceTransfer and SignatureTransfer.
Source excerpt · FinanceFeeds
A permit signature is a cryptographic authorization that allows a cryptocurrency holder to approve another address or smart contract to spend their tokens without first submitting a separate on-chain approval transaction. In traditional decentralized finance (DeFi), users typically complete two transactions before performing activities such as token swaps. First, they approve a smart contract to a…