EIP 1202: Voting Standard Source

AuthorZainan Victor Zhou, Evan, Yin Xu
TypeStandards Track

Simple Summary

Propose a standard interface for voting.


This proposal creates a standard API for implementing voting within smart contract. This standard provides functionalities to voting as well as to view the vote result and set voting status.


Voting is one of the earliest example of EVM programming, and also a key to DAO/organizational governance process. We foresee many DAOs will ultimately need to leverage voting as one of the important part of their governance. By creating a voting standard for smart contract / token, we can have the following benefits


  1. Allow general UI and applications to be built on top of a standardized voting to allow more general user to participate, and encourage more DApp and DAO to think about their governance
  2. Allow delegate voting / smart contract voting, automatic voting
  3. Allow voting results to be recorded on-chain, in a standard way, and allow DAOs and DApps to honor the voting result programmatically.
  4. Allow the compatibility with token standard such as ERC-20 or other new standards(EIP-777) and item standard such as EIP-721
  5. Create massive potential for interoperability within Ethereum echo systems and other system.
  6. Allow setting voting deadline, allow determine on single or multiple options. Allow requiring voting orders. (trade-off is interface complexity, we might need ERC-20 approach and later a EIP-777 for advanced voting)
  7. Recording the voting with weights with token amount.
  8. Possibly allow trust-worthy privacy-safe voting and anonymous voting (with either voter address being un-associated with the vote they cast, given a list of randomized/obfuscated voting options). 8
  9. Possibly allow result in reward by voting partitipation or voting result


  1. Determine on issuing new token, issuing more token or issuing sub-token
  2. Determine on creating new item under EIP-721
  3. Determine on election on certain person or smart contract to be delegated leader for project or subproject
  4. Determine on auditing result ownership allowing migration of smart contract proxy address


Simple Version

The simple version of specification makes the assumption that each smart contract voting standard is: Single Issue, Single Selection and Single Outcome

pragma solidity ^0.4.22;

 * - Single issue
 * - Single selection
 * Discussion:
 *   1. Each address has a weight determined by other input decided by the actual implementation
 *      which is suggested to be set upon the initialization
 *   2. Is there certain naming convention to follow?
interface ERC1202 {

    // Vote with an option. The caller needs to handle success or not
    function vote(uint option) external returns (bool success);
    function setStatus(bool isOpen) external returns (bool success);

    function issueDescription() external view returns (string desc);
    function availableOptions() external view returns (uint[] options);
    function optionDescription(uint option) external view returns (string desc);
    function ballotOf(address addr) external view returns (uint option);
    function weightOf(address addr) external view returns (uint weight);
    function getStatus() external view returns (bool isOpen);
    function weightedVoteCountsOf(uint option) external view returns (uint count);
    function winningOption() external view returns (uint option);

    event OnVote(address indexed _from, uint _value);
    event OnStatusChange(bool newIsOpen);

Advanced Version

pragma solidity ^0.4.22;

 * - Multiple issue
 * - Multiple selection
 * - Ordered multiple result
 * Discussion:
 *   1. Each address has a weight determined by other input decided by the actual implementation
 *      which is suggested to be set upon the initialization
 *   2. Is there certain naming convention to follow?
contract AdvancedERC1202 {

    // Vote with an option. The caller needs to handle success or not
    function vote(uint issueId, uint option) public returns (bool success);
    function setStatus(uint issueId, bool isOpen) public returns (bool success);

    function issueDescription(uint issueId) public view returns (string desc);
    function availableOptions(uint issueId) public view returns (uint[] options);
    function optionDescription(uint issueId, uint option) public view returns (string desc);
    function ballotOf(uint issueId, address addr) public view returns (uint option);
    function weightOf(uint issueId, address addr) public view returns (uint weight);
    function getStatus(uint issueId) public view returns (bool isOpen);
    function weightedVoteCountsOf(uint issueId, uint option) public view returns (uint count);
    function topOptions(uint issueId, uint limit) public view returns (uint[] topOptions_);

    event OnVote(uint issueId, address indexed _from, uint _value);
    event OnStatusChange(uint issueId, bool newIsOpen);


We made the following design decisions and here are the rationales.

  • Granularity and Anonymity:: We created a view function ballotOf primarily making it easier for people to check the vote from certain address. This has the following assumptions:

    • It’s possible to check someone’s vote directly given an address. If implementor don’t want to make it so easiy, they can simply reject all calls to this function. We want to make sure that we support both anonymous voting an non-anonymous voting. However since all calls to a smart contract is logged in block history, there is really no secrecy unless done with cryptography tricks. I am not cryptography-savvy enough to comment on the possibility. Please see “Second Feedback Questions 2018” for related topic.

    • It’s assumes for each individual address, they can only vote for one decision. They can distribute their available voting power into more granular level. If implementor wants allow this, they ask the user to create another wallet address and grant the new address certain power. For example, a token based voting where voting weight is determined by the amount of token held by a voter, a voter who wants to distribute its voting power in two different option(option set) can transfer some of the tokens to the new account and cast the votes from both accounts.

  • Weight: We assume there are weight of votes and can be checked by calling weightOf(address addr), and the weight distribution is either internally determined or determined by constructor. However we have not been considering updating the weight distribution. Please comment on this design decision as we want to learn how likely an implementor would want to be able to update the voting weight distributions.

Backward Compatibility

There is no backward compatibility issue we are aware of.

Simple Code Examples

Example 1: Simplest Version: Single Issue Yes/No Question Per Smart Contract Address Per Non-Weighted Vote

Example 2: TokenVote with Simple Interface with Weight Assigned by Token and Pre-registered Snapshot of Token-Holders

Example 3: TokenVote with Advanced Interface

Summary of Discussions

Early Feedback Questions (2018-07-08)

Here are a few early questions I’d like to ask people here.

  1. Have we had any duplicated EIPs that I overlooked. If not, have anyone attempted to do so, and why it did not continue to exist? Answer: We concluded there is no duplicated efforts working on creating a voting standard.

  2. Should each issue have its own smart contract address (like individual item on EIP-721) or should it support multiple items in EIP-1155, or should it support multi-class voting in EIP-1178, EIP-1203 (e.g. certain issue can override another issue) Answer: We will provide examples of both and seek comments.

  3. Should the voting support proxy(e.g EIP-897, EIP-1167) and migration? What are potential security concerns Answer: It shall not be determined by this ERC.

  4. Should it be proposed in a single phase standard or multiple separate into multiple phase, with earlier phase supporting easiest and simplest interface, and later phase supporting more advanced interfaces? (I intuitively believe it will be the latter, but not sure if it might be possible to do it all-at once.) Answer: It will unavoidably require upgrade in the future, but supporting multiple issue multiple options will be good enough so far.

  5. Should it support or optionally support EIP-165? For public voting, support EIP-165 make it easier to discover, but for secret voting people might not want to disclose a voting for certain issue even exist. Answer: It shall not be determined by this ERC.

Second Feedback Questions 2018-07-19

  1. Is it technically possible to achieve anonymous voting on current Ethereum/EVM setup, is it possible that people either hide their identity, or hide what selection they made in a vote given that for a smart contract the public states are visible from block history directly, and internal private state can be replied in any fullnode?

  2. number byte length: for simplicity we are using uint anywhere undecided. We need to decided what number byte length should we use for weights and options.


Worthnoting Projects


We appreciate Ansley, Andrew, Fred from Enigma, Fan and Raullen from IoTex for sharing us their use cases. we also appreciate the valuable input for designing an EIP from distinguished community members including: @frozeman, @fulldecent, @bingen, @aodhgan.

Work Directory

The drafting and revision of EIP-1202 is conducted at GitHub/xinbenlv/eip-1202

Copyright and related rights waived via CC0.