diff --git a/README.md b/README.md
index c9d9a128131d87179e5351b5067363347a7a916c..b2be360a1f4e004bd5524b5dde33eb92b1e73606 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,8 @@ This is only a quick demo on how you could possible generate a second factor in
 
 If you want to manage all your second factors in one place, this tool is not for you.
 
+A working implementation that even stores the secret somewhat securely is possible in a dozen lines of code, see the version on the tag [`initial`](https://gitlab.cl.uni-heidelberg.de/moser/2fa/-/blob/initial/main.py) for details.
+
 ## Installation
 
 ```bash