You can draw your signature with S Pen to unlock your Galaxy Note 3. This feature was more accurate than we expected and it was kind of fun enabling it.To set Signature screen lock on Galaxy Note 3, do as follows:
1. Open Settings and go to Device.
2. Open Lock Screen and then select Screen Lock.
3. Tap Signature, and use S Pen to register your signature by drawing it for 3 times.
4. Set a Backup PIN as an alternative to your signature
5. and you are Done
6. You can also uncheck Make Signature Visible to hide your drawing
7. Tap Accuracy Level and change it from Medium to Low or High for different accuracy level