Instead of using the home wallpaper, you can set a different wallpaper for your lock screen. 
	 
 
  
 
	 -  
		  	
Press and hold on an empty space on your Home screen.  
		
- Tap Theme.
-  
		  Tap 
			 . 
		   
		
-  
		  Tap 
			 Lock screen wallpaper. 
		   
		
- Select from the thumbnails or tap  to choose from your photos. to choose from your photos.
- Tap Apply or Save.