contract Exchange is Owned {
  function depositToken(address token, address target, uint256 amount) public returns (bool) {
    if (target == 0x0) target = msg.sender;
    require(acceptDeposit(token, target, amount));
    require(Token(token).transferFrom(msg.sender, this, amount));
    return true;
  }

  function deposit(address target) public payable returns (bool) {
    if (target == 0x0) target = msg.sender;
    require(acceptDeposit(0x0, target, msg.value));
    return true;
  }

  function trade(uint256[8] tradeValues, address[4] tradeAddresses, uint8[2] v, bytes32[4] rs) public onlyAdmin returns (bool) {
    /* amount is in amountBuy terms */
    /* tradeValues
       [0] amountBuy
       [1] amountSell
       [2] expires
       [3] nonce
       [4] amount
       [5] tradeNonce
       [6] feeMake
       [7] feeTake
     tradeAddressses
       [0] tokenBuy
       [1] tokenSell
       [2] maker
       [3] taker
     */
    ...
    bytes32 orderHash = keccak256(this, tradeAddresses[0], tradeValues[0], tradeAddresses[1], tradeValues[1], tradeValues[2], tradeValues[3], tradeAddresses[2]);
    bytes32 tradeHash = keccak256(orderHash, tradeValues[4], tradeAddresses[3], tradeValues[5]);
    ...
  }
}