Return to Ethereum ERCs

Note: The following is an excerpt from the official Ethereum site. It is provided here as a convenience and is not authoritative. Refer to the original document as the authoritative reference.

Signing data is a solved problem if all we care about are bytestrings. Unfortunately in the real world we care about complex meaningful messages. Hashing structured data is non-trivial and errors result in loss of the security properties of the system.

As such, the adage “don’t roll your own crypto” applies. Instead, a peer-reviewed well-tested standard method needs to be used. This EIP aims to be that standard.

This is a standard for hashing and signing of typed structured data as opposed to just bytestrings. It includes a

• theoretical framework for correctness of encoding functions,
• specification of structured data similar to and compatible with Solidity structs,
• safe hashing algorithm for instances of those structures,
• safe inclusion of those instances in the set of signable messages,
• an extensible mechanism for domain separation,
• new RPC call eth_signTypedData, and
• an optimized implementation of the hashing algorithm in EVM.

It does not include replay protection.