So maybe it's : d → f a → s n → m l → ; w → e d → f → fsm;ef (no).

Conclusion: not a simple adjacency shift. Try (A↔Z, B↔Y, etc.). 2. Try Atbash Cipher Atbash: A↔Z, B↔Y, C↔X, …, M↔N.

1. Check for Keyboard Layout Shift One common cause of seemingly random letters is typing with hands shifted one key to the right or left on a QWERTY keyboard.