             String(kSecAttrApplicationTag): self.privateTag as CFStringRef]
         
         let privateResult = SecItemDelete(query)
+    
+    //
+    //  MARK: Private types
+    //
+    private enum KeyType {
+        case Public
+        case Private
+    }
+    
         
         // Public key
         query = [

    }
    
    //
    //  Public functions
    //
    
    ///

        return false
    }
    
    
    //
    //  MARK: Private helpers
    //
    private func obtainKey(key: KeyType) -> SecKeyRef? {
        let tag: String = {
