Secure Access Controlling System

Hi Friends, I have a business and I want to control on unknown entries in my business so let me know how can it possible to prevent unknown entries in the door.

Honestly, there is no way. Best you can do is a keyed (electronic lock or physical key) entry door with a camera on the inside to record anyone who keys in.

Just make sure the camera can not be modified, and it feeds an offsite computer.

Thank you for reply.