How to limit execution of smart contract only to my dapp

Question

I want to limit the execution of my smart contract only to my dapp to avoid spoofing. How to do it?

Answer 1

You can use modifiers to do it like this:
pragma solidity ^0.4.0;

contract MyContract {
  address mAdmin;

  modifier adminOnly {
    if (msg.sender == mAdmin) _;
  }

  function MyContract() {
    mAdmin = msg.sender;
  }

  function doSomething() adminOnly {
    ...
  }
}

You can learn more about it here: http://solidity.readthedocs.io/en/develop/common-patterns.html#restricting-access