📖 This EIP is in the review stage. It is subject to changes and feedback is appreciated.

EIP-5008: EIP-721 Nonce Extension Source

Add a `nonce` function to EIP-721.

AuthorAnders, Lance, Shrug
Discussions-Tohttps://ethereum-magicians.org/t/eip5008-eip-721-nonce-and-metadata-update-extension/8925
StatusReview
TypeStandards Track
CategoryERC
Created2022-04-10
Requires 165, 721

Abstract

This standard is an extension of EIP-721. It proposes adding a nonce function to EIP-721 tokens.

Motivation

Some orders of NFT marketplaces have been attacked and the NFTs sold at a lower price than the current market floor price. This can happen when users transfer an NFT to another wallet and, later, back to the original wallet. This reactivates the order, which may list the token at a much lower price than the owner would have intended.

This EIP proposes adding a nonce property to EIP-721 tokens, and the nonce will be changed when a token is transferred. If a nonce is added to an order, the order can be checked to avoid attacks.

Specification

The keywords “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY” and “OPTIONAL” in this document are to be interpreted as described in RFC 2119.

interface IERC5008 /* is IERC165 */ {
    /// @notice Get the nonce of an NFT
    /// Throws if `tokenId` is not a valid NFT
    /// @param tokenId The id of the NFT
    /// @return The nonce of the NFT
    function nonce(uint256 tokenId) external view returns(uint256);
}

The nonce(uint256 tokenId) function MUST be implemented as view.

The supportsInterface method MUST return true when called with 0xce03fdab.

Rationale

At first transferCount was considered as function name, but there may some case to change the nonce besides transfer, such as important properties changed, then we changed transferCount to nonce.

Backwards Compatibility

This standard is compatible with EIP-721.

Test Cases

Test cases are included in test.js.

Run:

cd ../assets/eip-5008
npm install
npx hardhat test ./test/test.ts

Reference Implementation

See ERC5008.sol.

Security Considerations

No security issues found.

Copyright and related rights waived via CC0.

Citation

Please cite this document as:

Anders, Lance, Shrug, "EIP-5008: EIP-721 Nonce Extension [DRAFT]," Ethereum Improvement Proposals, no. 5008, April 2022. [Online serial]. Available: https://eips.ethereum.org/EIPS/eip-5008.