diff --git a/AddressRegistry.sol b/AddressRegistry.sol
index 5f97715..122e6ae 100644
--- a/AddressRegistry.sol
+++ b/AddressRegistry.sol
@@ -8,6 +8,7 @@ contract AddressRegistry {
 
     constructor() public {
         registry[keccak256(abi.encodePacked("admin"))] = msg.sender;
+        registry[keccak256(abi.encodePacked("owner"))] = msg.sender;
     }
 
     function getAddr(string memory name) public view returns(address) {
diff --git a/LogicProxy.sol b/LogicProxy.sol
index 1b5f85f..a836cfd 100644
--- a/LogicProxy.sol
+++ b/LogicProxy.sol
@@ -1,5 +1,6 @@
 pragma solidity ^0.4.23;
 
+
 interface AddrRegistry {
     function getAddr(string calldata name) external view returns(address);
 }
diff --git a/ProxyCache.sol b/ProxyCache.sol
deleted file mode 100644
index e0674e8..0000000
--- a/ProxyCache.sol
+++ /dev/null
@@ -1,32 +0,0 @@
-// DSProxyCache
-// This global cache stores addresses of contracts previously deployed
-// by a proxy. This saves gas from repeat deployment of the same
-// contracts and eliminates blockchain bloat.
-
-// By default, all proxies deployed from the same factory store
-// contracts in the same cache. The cache a proxy instance uses can be
-// changed.  The cache uses the sha3 hash of a contract's bytecode to
-// lookup the address
-pragma solidity ^0.4.23;
-
-contract DSProxyCache {
-    mapping(bytes32 => address) cache;
-
-    function read(bytes _code) public view returns (address) {
-        bytes32 hash = keccak256(_code);
-        return cache[hash];
-    }
-
-    function write(bytes _code) public returns (address target) {
-        assembly {
-            target := create(0, add(_code, 0x20), mload(_code))
-            switch iszero(extcodesize(target))
-            case 1 {
-                // throw if contract failed to deploy
-                revert(0, 0)
-            }
-        }
-        bytes32 hash = keccak256(_code);
-        cache[hash] = target;
-    }
-}
\ No newline at end of file
diff --git a/ProxyRegistry.sol b/ProxyRegistry.sol
index 37928f7..a7ff67a 100644
--- a/ProxyRegistry.sol
+++ b/ProxyRegistry.sol
@@ -1,5 +1,6 @@
 pragma solidity ^0.4.23;
 
+
 contract UserAuthority {
     function canCall(address src, address dst, bytes4 sig) public view returns (bool);
 }
@@ -77,35 +78,31 @@ contract UserNote {
     }
 }
 
+interface LogicRegistry {
+    function getLogic(address logicAddr) external view returns(bool);
+}
+
+contract LogicProxy {
+    address public logicProxyAddr;
+
+    function isLogic(address logicAddr) internal view returns(bool) {
+        LogicRegistry logicProxy = LogicRegistry(logicProxyAddr);
+        return logicProxy.getLogic(logicAddr);
+    }
+}
+
 // UserProxy
 // Allows code execution using a persistant identity This can be very
 // useful to execute a sequence of atomic actions. Since the owner of
 // the proxy can be changed, this allows for dynamic ownership models
 // i.e. a multisig
-contract UserProxy is UserAuth, UserNote {
-    UserProxyCache public cache;  // global cache for contracts
+contract UserProxy is UserAuth, UserNote, LogicProxy {
 
-    constructor(address _cacheAddr) public {
-        setCache(_cacheAddr);
+    constructor(address logicProxyAddr_) public {
+        logicProxyAddr = logicProxyAddr_;
     }
 
-    function() external payable {
-    }
-
-    // use the proxy to execute calldata _data on contract _code
-    function execute(bytes memory _code, bytes memory _data)
-        public
-        payable
-        returns (address target, bytes memory response)
-    {
-        target = cache.read(_code);
-        if (target == address(0)) {
-            // deploy contract & store its address in cache
-            target = cache.write(_code);
-        }
-
-        response = execute(target, _data);
-    }
+    function() external payable {}
 
     function execute(address _target, bytes memory _data)
         public
@@ -114,7 +111,8 @@ contract UserProxy is UserAuth, UserNote {
         payable
         returns (bytes memory response)
     {
-        require(_target != address(0), "User-proxy-target-address-required");
+        require(_target != address(0), "user-proxy-target-address-required");
+        require(isLogic(_target), "invalid-logic-proxy-address");
 
         // call contract in current context
         assembly {
@@ -133,68 +131,29 @@ contract UserProxy is UserAuth, UserNote {
             }
         }
     }
-
-    //set new cache
-    function setCache(address _cacheAddr)
-        public
-        auth
-        note
-        returns (bool)
-    {
-        require(_cacheAddr != address(0), "User-proxy-cache-address-required");
-        cache = UserProxyCache(_cacheAddr);  // overwrite cache
-        return true;
-    }
-}
-
-// UserProxyCache
-// This global cache stores addresses of contracts previously deployed
-// by a proxy. This saves gas from repeat deployment of the same
-// contracts and eliminates blockchain bloat.
-
-// By default, all proxies deployed from the same factory store
-// contracts in the same cache. The cache a proxy instance uses can be
-// changed.  The cache uses the sha3 hash of a contract's bytecode to
-// lookup the address
-contract UserProxyCache {
-    mapping(bytes32 => address) cache;
-
-    function read(bytes memory _code) public view returns (address) {
-        bytes32 hash = keccak256(_code);
-        return cache[hash];
-    }
-
-    function write(bytes memory _code) public returns (address target) {
-        assembly {
-            target := create(0, add(_code, 0x20), mload(_code))
-            switch iszero(extcodesize(target))
-            case 1 {
-                // throw if contract failed to deploy
-                revert(0, 0)
-            }
-        }
-        bytes32 hash = keccak256(_code);
-        cache[hash] = target;
-    }
 }
 
 // ProxyRegistry
 contract ProxyRegistry {
     event Created(address indexed sender, address indexed owner, address proxy);
-    mapping(address => DSProxy) public proxies;
-    DSProxyCache cache = new DSProxyCache();
+    mapping(address => UserProxy) public proxies;
+    address public logicProxyAddr;
+
+    constructor(address logicProxyAddr_) public {
+        logicProxyAddr = logicProxyAddr_;
+    }
 
     // deploys a new proxy instance
     // sets owner of proxy to caller
-    function build() public returns (DSProxy proxy) {
+    function build() public returns (UserProxy proxy) {
         proxy = build(msg.sender);
     }
 
     // deploys a new proxy instance
     // sets custom owner of proxy
-    function build(address owner) public returns (DSProxy proxy) {
-        require(proxies[owner] == DSProxy(0) || proxies[owner].owner() != owner); // Not allow new proxy if the user already has one and remains being the owner
-        proxy = new DSProxy(cache);
+    function build(address owner) public returns (UserProxy proxy) {
+        require(proxies[owner] == UserProxy(0) || proxies[owner].owner() != owner); // Not allow new proxy if the user already has one and remains being the owner
+        proxy = new UserProxy(logicProxyAddr);
         emit Created(msg.sender, owner, address(proxy));
         proxy.setOwner(owner);
         proxies[owner] = proxy;
diff --git a/UserProxy.sol b/UserProxy.sol
index 7486ec7..897c85a 100644
--- a/UserProxy.sol
+++ b/UserProxy.sol
@@ -1,5 +1,6 @@
 pragma solidity ^0.4.23;
 
+
 contract UserAuthority {
     function canCall(address src, address dst, bytes4 sig) public view returns (bool);
 }
@@ -77,35 +78,31 @@ contract UserNote {
     }
 }
 
+interface LogicRegistry {
+    function getLogic(address logicAddr) external view returns(bool);
+}
+
+contract LogicProxy {
+    address public logicProxyAddr;
+
+    function isLogic(address logicAddr) internal view returns(bool) {
+        LogicRegistry logicProxy = LogicRegistry(logicProxyAddr);
+        return logicProxy.getLogic(logicAddr);
+    }
+}
+
 // UserProxy
 // Allows code execution using a persistant identity This can be very
 // useful to execute a sequence of atomic actions. Since the owner of
 // the proxy can be changed, this allows for dynamic ownership models
 // i.e. a multisig
-contract UserProxy is UserAuth, UserNote {
-    UserProxyCache public cache;  // global cache for contracts
+contract UserProxy is UserAuth, UserNote, LogicProxy {
 
-    constructor(address _cacheAddr) public {
-        setCache(_cacheAddr);
+    constructor(address logicProxyAddr_) public {
+        logicProxyAddr = logicProxyAddr_;
     }
 
-    function() external payable {
-    }
-
-    // use the proxy to execute calldata _data on contract _code
-    function execute(bytes memory _code, bytes memory _data)
-        public
-        payable
-        returns (address target, bytes memory response)
-    {
-        target = cache.read(_code);
-        if (target == address(0)) {
-            // deploy contract & store its address in cache
-            target = cache.write(_code);
-        }
-
-        response = execute(target, _data);
-    }
+    function() external payable {}
 
     function execute(address _target, bytes memory _data)
         public
@@ -114,7 +111,8 @@ contract UserProxy is UserAuth, UserNote {
         payable
         returns (bytes memory response)
     {
-        require(_target != address(0), "User-proxy-target-address-required");
+        require(_target != address(0), "user-proxy-target-address-required");
+        require(isLogic(_target), "invalid-logic-proxy-address");
 
         // call contract in current context
         assembly {
@@ -133,47 +131,4 @@ contract UserProxy is UserAuth, UserNote {
             }
         }
     }
-
-    //set new cache
-    function setCache(address _cacheAddr)
-        public
-        auth
-        note
-        returns (bool)
-    {
-        require(_cacheAddr != address(0), "User-proxy-cache-address-required");
-        cache = UserProxyCache(_cacheAddr);  // overwrite cache
-        return true;
-    }
-}
-
-// UserProxyCache
-// This global cache stores addresses of contracts previously deployed
-// by a proxy. This saves gas from repeat deployment of the same
-// contracts and eliminates blockchain bloat.
-
-// By default, all proxies deployed from the same factory store
-// contracts in the same cache. The cache a proxy instance uses can be
-// changed.  The cache uses the sha3 hash of a contract's bytecode to
-// lookup the address
-contract UserProxyCache {
-    mapping(bytes32 => address) cache;
-
-    function read(bytes memory _code) public view returns (address) {
-        bytes32 hash = keccak256(_code);
-        return cache[hash];
-    }
-
-    function write(bytes memory _code) public returns (address target) {
-        assembly {
-            target := create(0, add(_code, 0x20), mload(_code))
-            switch iszero(extcodesize(target))
-            case 1 {
-                // throw if contract failed to deploy
-                revert(0, 0)
-            }
-        }
-        bytes32 hash = keccak256(_code);
-        cache[hash] = target;
-    }
 }
\ No newline at end of file