diff --git a/RMDEC/VXAProject.cs b/RMDEC/VXAProject.cs
index 6c45e76..bbeace0 100644
--- a/RMDEC/VXAProject.cs
+++ b/RMDEC/VXAProject.cs
@@ -137,6 +137,8 @@ namespace RMDEC
             byte[] output = new byte[size];
 
             uint keyInt = BitConverter.ToUInt32(keydata, 0x00);
+            byte[] derivedKeyData = new byte[keydata.Length];
+            Array.Copy(keydata, derivedKeyData, 0x4);
 
             for (int i = 0; i < size; i++)
             {
@@ -144,16 +146,17 @@ namespace RMDEC
                 {
                     // Derive new key
                     keyInt = ((keyInt * 7) + 3);
-
-                    byte[] derivedKeyBytes = BitConverter.GetBytes(keyInt);
-                    Array.Copy(derivedKeyBytes, keydata, 0x4); // have to do this in order to make the arguments update..
-                    
+                    derivedKeyData = BitConverter.GetBytes(keyInt);
                 }
 
-                output[i] = (byte)(input[i] ^ keydata[i % keydata.Length]);
-                
+                output[i] = (byte)(input[i] ^ derivedKeyData[i % derivedKeyData.Length]);
             }
 
+            //Final Derive (incase of >MAX_SIZE)
+            keyInt = ((keyInt * 7) + 3);
+            derivedKeyData = BitConverter.GetBytes(keyInt);
+            Array.Copy(derivedKeyData, keydata, 0x4);
+
             return output;
         }
         
@@ -198,20 +201,23 @@ namespace RMDEC
 
         public void DecryptFile(int fileIndex, Stream outStream)
         {
+            int MAX_SIZE = 0x20000000; //512MB (MUST BE DIVISIBLE BY 4)
+
             outStream.SetLength(0);
             ArchiveFile fileData = archiveFileList[fileIndex];
             byte[] keyData = fileData.Key;
 
             rgss3aStream.Seek(fileData.Offset, SeekOrigin.Begin);
             uint size = fileData.Size;
+            
 
-            for(int i = 0; i < size; i += 0x20000000)
+            for (int i = 0; i < size; i += MAX_SIZE)
             {
                 
-                if (size > 0x20000000) //512MB
+                if (size > MAX_SIZE)
                 {
-                    byte[] gameData = new byte[0x20000000];
-                    rgss3aStream.Read(gameData, 0x00, 0x20000000);
+                    byte[] gameData = new byte[MAX_SIZE];
+                    rgss3aStream.Read(gameData, 0x00, MAX_SIZE);
                     gameData = decryptFileData(gameData, keyData);
                     outStream.Write(gameData, 0x00, gameData.Length);
                 }