I am currently working on a product similar to smart locks that work with BLE identification. I can handle the hardware of the product very well (mechanics / electronics / embedded software), however, I am totally unaware of how to implement the security layer in the product and how to validate it if exists.
Rudeness not intended: if you are unaware of how to implement security on a lock, you must not even try to implement security on a lock.
No matter how good with the hardware and electronics you are, if the security is done by someone unexperienced, it is worse than no lock at all.
Why? Because if there's no lock on the door, people will not put anything valuable behind it. If there's your smart lock with flawed security, people will not know that, protect their valuables with your lock, and guess what...
Hire someone to do it for you. You don't have to make everything. In this case, you are not allowed to do everything.
And after hiring someone to implement security, get the schematics, a couple locks, and hire someone else to break the security. The someone else is very important.