diff --git a/README.md b/README.md
index 8c9f009..e1e32b9 100644
--- a/README.md
+++ b/README.md
@@ -15,7 +15,10 @@ We suggest printing the model using more than one filament color to make the
 letters easily recognizable. Thanks go to Martin Ptasek for providing the
 picture.
 
-If you trust your computer, there is now a python implementation in `ls47.py`.
+If you trust your computer, there is now a very simple python implementation in
+`ls47.py`. A much better version usuable as an actual binary (also supporting
+several versions of padding and the original ElsieFour cipher) was supplied by
+Bernhard Esslinger from the CrypTool project, available in `lc4.py`.
 
 ### Character board