# ERC-712: Typed structured data hashing and signing Content type: Research Paper Summary: ERC-712 introduces a standardized method for hashing and signing complex, typed structured data within the Ethereum ecosystem. Before this standard, signing arbitrary data required users to hash and sign opaque byte arrays, which lacked human readability and context. ERC-712 solves this by requiring a domain separator and a schema definition, ensuring that signatures are context-aware and verifiable against specific smart contracts or chains. This mechanism significantly improves user security b Key concepts: Remco Bloemen, Vikas Dhillon, Dan Finlay, ethereum, signing, security, eip, cryptography
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ERC-712: Typed structured data hashing and signing

Remco Bloemen, Vikas Dhillon, Dan Finlay

Ethereum Improvement ProposalsJanuary 2019

Abstract

ERC-712 introduces a standardized method for hashing and signing complex, typed structured data within the Ethereum ecosystem. Before this standard, signing arbitrary data required users to hash and sign opaque byte arrays, which lacked human readability and context. ERC-712 solves this by requiring a domain separator and a schema definition, ensuring that signatures are context-aware and verifiable against specific smart contracts or chains. This mechanism significantly improves user security by allowing wallet interfaces to parse the structured data, enabling users to understand exactly what they are signing before granting approval. The standard provides a formal specification for how domain descriptors and typed data are encoded, hashed (often using Keccak-256), and then signed using ECDSA or other signature schemes. Its implementation has become foundational for off-chain signaling, gasless transactions, and complex permit-based approvals in decentralized finance (DeFi). By bridging the gap between raw data and human-understandable information, ERC-712 enhances the usability and trustworthiness of dapp interactions, effectively reducing the risk of blind signing in complex smart contract operations.

Key Findings

  • 1Enables secure and human-readable signing of structured data in Ethereum applications.
  • 2Prevents signature replay attacks across different chains or dapps via domain separators.
  • 3Facilitates improved wallet UX by providing structure for transaction verification.
  • 4Standardizes the serialization and signing processes for typed data structures.

Topics

ethereumsigningsecurityeipcryptography
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Citation

Remco Bloemen, Vikas Dhillon, Dan Finlay (2019). ERC-712: Typed structured data hashing and signing. Ethereum Improvement Proposals. https://eips.ethereum.org/EIPS/eip-712

BibTeX

@misc{erc7122019,
  title = {ERC-712: Typed structured data hashing and signing},
  author = {Remco Bloemen and Vikas Dhillon and Dan Finlay},
  year = {2019},
  howpublished = {\url{https://eips.ethereum.org/EIPS/eip-712}},
}

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