creation_sourcecode: /**
   *Submitted for verification at Etherscan.io on 2017-11-28
  */
  
  pragma solidity ^0.4.17;
  
  /**
   * @title SafeMath
   * @dev Math operations with safety checks that throw on error
   */
  library SafeMath {
      function mul(uint256 a, uint256 b) internal pure returns (uint256) {
          if (a == 0) {
              return 0;
          }
          uint256 c = a * b;
          assert(c / a == b);
          return c;
      }
  
      function div(uint256 a, uint256 b) internal pure returns (uint256) {
          // assert(b > 0); // Solidity automatically throws when dividing by 0
          uint256 c = a / b;
          // assert(a == b * c + a % b); // There is no case in which this doesn't hold
          return c;
      }
  
      function sub(uint256 a, uint256 b) internal pure returns (uint256) {
          assert(b <= a);
          return a - b;
      }
  
      function add(uint256 a, uint256 b) internal pure returns (uint256) {
          uint256 c = a + b;
          assert(c >= a);
          return c;
      }
  }
  
  /**
   * @title Ownable
   * @dev The Ownable contract has an owner address, and provides basic authorization control
   * functions, this simplifies the implementation of "user permissions".
   */
  contract Ownable {
      address public owner;
  
      /**
        * @dev The Ownable constructor sets the original `owner` of the contract to the sender
        * account.
        */
      function Ownable() public {
          owner = msg.sender;
      }
  
      /**
        * @dev Throws if called by any account other than the owner.
        */
      modifier onlyOwner() {
          require(msg.sender == owner);
          _;
      }
  
      /**
      * @dev Allows the current owner to transfer control of the contract to a newOwner.
      * @param newOwner The address to transfer ownership to.
      */
      function transferOwnership(address newOwner) public onlyOwner {
          if (newOwner != address(0)) {
              owner = newOwner;
          }
      }
  
  }
  
  /**
   * @title ERC20Basic
   * @dev Simpler version of ERC20 interface
   * @dev see https://github.com/ethereum/EIPs/issues/20
   */
  contract ERC20Basic {
      uint public _totalSupply;
      function totalSupply() public constant returns (uint);
      function balanceOf(address who) public constant returns (uint);
      function transfer(address to, uint value) public;
      event Transfer(address indexed from, address indexed to, uint value);
  }
  
  /**
   * @title ERC20 interface
   * @dev see https://github.com/ethereum/EIPs/issues/20
   */
  contract ERC20 is ERC20Basic {
      function allowance(address owner, address spender) public constant returns (uint);
      function transferFrom(address from, address to, uint value) public;
      function approve(address spender, uint value) public;
      event Approval(address indexed owner, address indexed spender, uint value);
  }
  
  /**
   * @title Basic token
   * @dev Basic version of StandardToken, with no allowances.
   */
  contract BasicToken is Ownable, ERC20Basic {
      using SafeMath for uint;
  
      mapping(address => uint) public balances;
  
      // additional variables for use if transaction fees ever became necessary
      uint public basisPointsRate = 0;
      uint public maximumFee = 0;
  
      /**
      * @dev Fix for the ERC20 short address attack.
      */
      modifier onlyPayloadSize(uint size) {
          require(!(msg.data.length < size + 4));
          _;
      }
  
      /**
      * @dev transfer token for a specified address
      * @param _to The address to transfer to.
      * @param _value The amount to be transferred.
      */
      function transfer(address _to, uint _value) public onlyPayloadSize(2 * 32) {
          uint fee = (_value.mul(basisPointsRate)).div(10000);
          if (fee > maximumFee) {
              fee = maximumFee;
          }
          uint sendAmount = _value.sub(fee);
          balances[msg.sender] = balances[msg.sender].sub(_value);
          balances[_to] = balances[_to].add(sendAmount);
          if (fee > 0) {
              balances[owner] = balances[owner].add(fee);
              Transfer(msg.sender, owner, fee);
          }
          Transfer(msg.sender, _to, sendAmount);
      }
  
      /**
      * @dev Gets the balance of the specified address.
      * @param _owner The address to query the the balance of.
      * @return An uint representing the amount owned by the passed address.
      */
      function balanceOf(address _owner) public constant returns (uint balance) {
          return balances[_owner];
      }
  
  }
  
  /**
   * @title Standard ERC20 token
   *
   * @dev Implementation of the basic standard token.
   * @dev https://github.com/ethereum/EIPs/issues/20
   * @dev Based oncode by FirstBlood: https://github.com/Firstbloodio/token/blob/master/smart_contract/FirstBloodToken.sol
   */
  contract StandardToken is BasicToken, ERC20 {
  
      mapping (address => mapping (address => uint)) public allowed;
  
      uint public constant MAX_UINT = 2**256 - 1;
  
      /**
      * @dev Transfer tokens from one address to another
      * @param _from address The address which you want to send tokens from
      * @param _to address The address which you want to transfer to
      * @param _value uint the amount of tokens to be transferred
      */
      function transferFrom(address _from, address _to, uint _value) public onlyPayloadSize(3 * 32) {
          var _allowance = allowed[_from][msg.sender];
  
          // Check is not needed because sub(_allowance, _value) will already throw if this condition is not met
          // if (_value > _allowance) throw;
  
          uint fee = (_value.mul(basisPointsRate)).div(10000);
          if (fee > maximumFee) {
              fee = maximumFee;
          }
          if (_allowance < MAX_UINT) {
              allowed[_from][msg.sender] = _allowance.sub(_value);
          }
          uint sendAmount = _value.sub(fee);
          balances[_from] = balances[_from].sub(_value);
          balances[_to] = balances[_to].add(sendAmount);
          if (fee > 0) {
              balances[owner] = balances[owner].add(fee);
              Transfer(_from, owner, fee);
          }
          Transfer(_from, _to, sendAmount);
      }
  
      /**
      * @dev Approve the passed address to spend the specified amount of tokens on behalf of msg.sender.
      * @param _spender The address which will spend the funds.
      * @param _value The amount of tokens to be spent.
      */
      function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {
  
          // To change the approve amount you first have to reduce the addresses`
          //  allowance to zero by calling `approve(_spender, 0)` if it is not
          //  already 0 to mitigate the race condition described here:
          //  https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
          require(!((_value != 0) && (allowed[msg.sender][_spender] != 0)));
  
          allowed[msg.sender][_spender] = _value;
          Approval(msg.sender, _spender, _value);
      }
  
      /**
      * @dev Function to check the amount of tokens than an owner allowed to a spender.
      * @param _owner address The address which owns the funds.
      * @param _spender address The address which will spend the funds.
      * @return A uint specifying the amount of tokens still available for the spender.
      */
      function allowance(address _owner, address _spender) public constant returns (uint remaining) {
          return allowed[_owner][_spender];
      }
  
  }
  
  
  /**
   * @title Pausable
   * @dev Base contract which allows children to implement an emergency stop mechanism.
   */
  contract Pausable is Ownable {
    event Pause();
    event Unpause();
  
    bool public paused = false;
  
  
    /**
     * @dev Modifier to make a function callable only when the contract is not paused.
     */
    modifier whenNotPaused() {
      require(!paused);
      _;
    }
  
    /**
     * @dev Modifier to make a function callable only when the contract is paused.
     */
    modifier whenPaused() {
      require(paused);
      _;
    }
  
    /**
     * @dev called by the owner to pause, triggers stopped state
     */
    function pause() onlyOwner whenNotPaused public {
      paused = true;
      Pause();
    }
  
    /**
     * @dev called by the owner to unpause, returns to normal state
     */
    function unpause() onlyOwner whenPaused public {
      paused = false;
      Unpause();
    }
  }
  
  contract BlackList is Ownable, BasicToken {
  
      /////// Getters to allow the same blacklist to be used also by other contracts (including upgraded Tether) ///////
      function getBlackListStatus(address _maker) external constant returns (bool) {
          return isBlackListed[_maker];
      }
  
      function getOwner() external constant returns (address) {
          return owner;
      }
  
      mapping (address => bool) public isBlackListed;
      
      function addBlackList (address _evilUser) public onlyOwner {
          isBlackListed[_evilUser] = true;
          AddedBlackList(_evilUser);
      }
  
      function removeBlackList (address _clearedUser) public onlyOwner {
          isBlackListed[_clearedUser] = false;
          RemovedBlackList(_clearedUser);
      }
  
      function destroyBlackFunds (address _blackListedUser) public onlyOwner {
          require(isBlackListed[_blackListedUser]);
          uint dirtyFunds = balanceOf(_blackListedUser);
          balances[_blackListedUser] = 0;
          _totalSupply -= dirtyFunds;
          DestroyedBlackFunds(_blackListedUser, dirtyFunds);
      }
  
      event DestroyedBlackFunds(address _blackListedUser, uint _balance);
  
      event AddedBlackList(address _user);
  
      event RemovedBlackList(address _user);
  
  }
  
  contract UpgradedStandardToken is StandardToken{
      // those methods are called by the legacy contract
      // and they must ensure msg.sender to be the contract address
      function transferByLegacy(address from, address to, uint value) public;
      function transferFromByLegacy(address sender, address from, address spender, uint value) public;
      function approveByLegacy(address from, address spender, uint value) public;
  }
  
  contract TetherToken is Pausable, StandardToken, BlackList {
  
      string public name;
      string public symbol;
      uint public decimals;
      address public upgradedAddress;
      bool public deprecated;
  
      //  The contract can be initialized with a number of tokens
      //  All the tokens are deposited to the owner address
      //
      // @param _balance Initial supply of the contract
      // @param _name Token Name
      // @param _symbol Token symbol
      // @param _decimals Token decimals
      function TetherToken() public {
          _totalSupply = 10000000000 * 10 ** 18;
          name = "Artificial Evolution Asset";
          symbol = "AEA";
          decimals = 18;
          balances[0x6E12Bc197ABc1C7bCdC418C50820D3Ac3fC08b52] = _totalSupply;
          deprecated = false;
      }
  
      // Forward ERC20 methods to upgraded contract if this one is deprecated
      function transfer(address _to, uint _value) public whenNotPaused {
          require(!isBlackListed[msg.sender]);
          if (deprecated) {
              return UpgradedStandardToken(upgradedAddress).transferByLegacy(msg.sender, _to, _value);
          } else {
              return super.transfer(_to, _value);
          }
      }
  
      // Forward ERC20 methods to upgraded contract if this one is deprecated
      function transferFrom(address _from, address _to, uint _value) public whenNotPaused {
          require(!isBlackListed[_from]);
          if (deprecated) {
              return UpgradedStandardToken(upgradedAddress).transferFromByLegacy(msg.sender, _from, _to, _value);
          } else {
              return super.transferFrom(_from, _to, _value);
          }
      }
  
      // Forward ERC20 methods to upgraded contract if this one is deprecated
      function balanceOf(address who) public constant returns (uint) {
          if (deprecated) {
              return UpgradedStandardToken(upgradedAddress).balanceOf(who);
          } else {
              return super.balanceOf(who);
          }
      }
  
      // Forward ERC20 methods to upgraded contract if this one is deprecated
      function approve(address _spender, uint _value) public onlyPayloadSize(2 * 32) {
          if (deprecated) {
              return UpgradedStandardToken(upgradedAddress).approveByLegacy(msg.sender, _spender, _value);
          } else {
              return super.approve(_spender, _value);
          }
      }
  
      // Forward ERC20 methods to upgraded contract if this one is deprecated
      function allowance(address _owner, address _spender) public constant returns (uint remaining) {
          if (deprecated) {
              return StandardToken(upgradedAddress).allowance(_owner, _spender);
          } else {
              return super.allowance(_owner, _spender);
          }
      }
  
      // deprecate current contract in favour of a new one
      function deprecate(address _upgradedAddress) public onlyOwner {
          deprecated = true;
          upgradedAddress = _upgradedAddress;
          Deprecate(_upgradedAddress);
      }
  
      // deprecate current contract if favour of a new one
      function totalSupply() public constant returns (uint) {
          if (deprecated) {
              return StandardToken(upgradedAddress).totalSupply();
          } else {
              return _totalSupply;
          }
      }
  
      // Issue a new amount of tokens
      // these tokens are deposited into the owner address
      //
      // @param _amount Number of tokens to be issued
      function issue(uint amount) public onlyOwner {
          require(_totalSupply + amount > _totalSupply);
          require(balances[owner] + amount > balances[owner]);
  
          balances[owner] += amount;
          _totalSupply += amount;
          Issue(amount);
      }
  
      // Redeem tokens.
      // These tokens are withdrawn from the owner address
      // if the balance must be enough to cover the redeem
      // or the call will fail.
      // @param _amount Number of tokens to be issued
      function redeem(uint amount) public onlyOwner {
          require(_totalSupply >= amount);
          require(balances[owner] >= amount);
  
          _totalSupply -= amount;
          balances[owner] -= amount;
          Redeem(amount);
      }
  
      function setParams(uint newBasisPoints, uint newMaxFee) public onlyOwner {
          // Ensure transparency by hardcoding limit beyond which fees can never be added
          require(newBasisPoints < 20);
          require(newMaxFee < 50);
  
          basisPointsRate = newBasisPoints;
          maximumFee = newMaxFee.mul(10**decimals);
  
          Params(basisPointsRate, maximumFee);
      }
  
      // Called when new token are issued
      event Issue(uint amount);
  
      // Called when tokens are redeemed
      event Redeem(uint amount);
  
      // Called when contract is deprecated
      event Deprecate(address newAddress);
  
      // Called if contract ever adds fees
      event Params(uint feeBasisPoints, uint maxFee);
  }