イーサリアムのスマートコントラクト、ビットコインのような複数署名できる？ ref: https://qiita.com/blueplanet/items/1d81302f35e426e81485

file0.txt

pragma solidity ^0.4.17;

contract MultiVoteTransfer {
  address[] voterAddresses;
  mapping(address => bool) votes;
  bool public transfered;

  modifier onlyVoter() {
    bool isVoter = false;

    for (uint i = 0; i < voterAddresses.length; i++) {
      if (voterAddresses[i] == msg.sender) {
        isVoter = true;
      }
    }

    require(isVoter);
    _;
  }

  function MultiVoteTransfer(address[] _voterAddresses) public {
    voterAddresses = _voterAddresses;
    transfered = false;
  }

  function sign() public onlyVoter returns (bool) {
    votes[msg.sender] = true;

    bool allVoted = true;

    for (uint i = 0; i < voterAddresses.length; i++) {
      if (votes[voterAddresses[i]] == false) {
        allVoted = false;
      }
    }

    if (allVoted == true) {
        // 送金処理とか
        transfered = true;
    }
  }
}