diff --git a/contracts/ethPool.sol b/contracts/ethPool.sol
index 740a3c9..b3873b7 100644
--- a/contracts/ethPool.sol
+++ b/contracts/ethPool.sol
@@ -136,7 +136,7 @@ contract PoolToken is ERC20, DSMath {
 
         _burn(msg.sender, _burnAmt);
 
-        payable(to).transfer(_tknAmt);
+        payable(to).transfer(_tknAmt); // TODO - if this is also Reentrancy prone attack or not.
 
         emit LogWithdraw(tknAmt, _burnAmt);
     }
diff --git a/contracts/rateLogics/dai.sol b/contracts/rateLogics/dai.sol
index 4088a94..0928393 100644
--- a/contracts/rateLogics/dai.sol
+++ b/contracts/rateLogics/dai.sol
@@ -25,16 +25,7 @@ contract RateLogic is DSMath {
     CTokenInterface ctoken = CTokenInterface(address(0));
     CTokenInterface token = CTokenInterface(address(0));
 
-    uint fee = 1e17; // 10%
-    function totalBalanceDSA() public view returns (uint) {
-        address _dsa;
-        uint abal = atoken.balanceOf(_dsa);
-        uint cbal = wmul(ctoken.balanceOf(_dsa), ctoken.getExchangeRate());
-        uint bal = token.balanceOf(_dsa);
-        return add(abal, add(cbal, bal));
-    }
-
-    function totalBalance() public view returns (uint) {
+    function getTotalToken() public view returns (uint) {
         address _dsa;
         uint abal = atoken.balanceOf(_dsa);
         uint cbal = wmul(ctoken.balanceOf(_dsa), ctoken.getExchangeRate());
@@ -42,13 +33,4 @@ contract RateLogic is DSMath {
         uint poolBal = token.balanceOf(address(poolToken));
         return add(add(abal, poolBal) , add(cbal, dsaBal));
     }
-
-    function pricePerToken() public view returns(uint256) {
-        // TODO - add security logic
-        uint _totalBalance = totalBalanceDSA();
-        uint profit = sub(_totalBalance, poolToken.dsaAmount());
-        uint leftProfit = wmul(profit, fee);
-        uint leftTotalBalance = add(leftProfit, poolToken.dsaAmount());
-        return wdiv(leftTotalBalance, poolToken.totalSupply());
-    }
 }
diff --git a/contracts/registry.sol b/contracts/registry.sol
index 375b708..acc74f1 100644
--- a/contracts/registry.sol
+++ b/contracts/registry.sol
@@ -11,6 +11,8 @@ contract Registry {
 
   event LogAddChief(address indexed chief);
   event LogRemoveChief(address indexed chief);
+  event LogAddSigner(address indexed signer);
+  event LogRemoveSigner(address indexed signer);
   event LogSwitchPool(address pool, bool);
   event LogUpdatePoolCap(address pool, uint newCap);
   event LogUpdatePoolLogic(address pool, address newLogic);
@@ -19,6 +21,7 @@ contract Registry {
   IndexInterface public constant instaIndex = IndexInterface(0x2971AdFa57b20E5a416aE5a708A8655A9c74f723);
 
   mapping (address => bool) public chief;
+  mapping (address => bool) public signer;
   mapping (address => bool) public isPool;
   mapping (address => address) public poolLogic;
   mapping (address => uint) public poolCap;
@@ -56,6 +59,28 @@ contract Registry {
     emit LogRemoveChief(_chief);
   }
 
+  /**
+    * @dev Enable New Signer.
+    * @param _signer Address of the new signer.
+  */
+  function enableSigner(address _signer) external isChief {
+      require(_signer != address(0), "address-not-valid");
+      require(!signer[_signer], "signer-already-enabled");
+      signer[_signer] = true;
+      emit LogAddSigner(_signer);
+  }
+
+  /**
+    * @dev Disable Signer.
+    * @param _signer Address of the existing signer.
+  */
+  function disableSigner(address _signer) external isChief {
+      require(_signer != address(0), "address-not-valid");
+      require(signer[_signer], "signer-already-disabled");
+      delete signer[_signer];
+      emit LogRemoveSigner(_signer);
+  }
+
   function switchPool(address _pool) external isMaster {
     isPool[_pool] = !isPool[_pool];
     emit LogSwitchPool(_pool, isPool[_pool]);
@@ -84,6 +109,5 @@ contract Registry {
   constructor(address _chief) public {
     chief[_chief] = true;
     emit LogAddChief(_chief);
-  }
-  
+  } 
 }
diff --git a/contracts/tokenPool.sol b/contracts/tokenPool.sol
index 36202a4..64f2d95 100644
--- a/contracts/tokenPool.sol
+++ b/contracts/tokenPool.sol
@@ -3,7 +3,6 @@ pragma solidity ^0.6.8;
 pragma experimental ABIEncoderV2;
 
 import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
-import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import "@openzeppelin/contracts/token/ERC20/SafeERC20.sol";
 
 import { DSMath } from "./libs/safeMath.sol";
@@ -26,7 +25,6 @@ interface RegistryInterface {
 }
 
 interface RateInterface {
-  function totalBalance() external view returns (uint);
   function getTotalToken() external returns (uint totalUnderlyingTkn);
 }
 
@@ -47,7 +45,7 @@ contract PoolToken is ERC20, DSMath {
     AccountInterface public immutable dsa; // Pool's DSA account
 
     uint private tokenBalance; // total token balance since last rebalancing
-    uint public exchangeRate = 1000000000000000000; // initial 1 token = 1
+    uint public exchangeRate = 10 ** 18; // initial 1 token = 1
     uint public insuranceAmt; // insurance amount to keep pool safe
     bool public shutPool; // shutdown deposits and withdrawals
 
@@ -85,7 +83,7 @@ contract PoolToken is ERC20, DSMath {
             _currentRate = _previousRate;
         } else {
             uint difRate = _currentRate - _previousRate;
-            uint insureFee = wmul(difRate, registry.insureFee(address(this))); // 1e17
+            uint insureFee = wmul(difRate, registry.insureFee(address(this)));
             uint insureFeeAmt = wmul(_totalToken, insureFee);
             insuranceAmt = add(insuranceAmt, insureFeeAmt);
             _currentRate = sub(_currentRate, insureFee);