Is it safe to open ssh port to world with only key based authentication?

[Vijay Gill]

I am working on the idea of writing a small script which will modify
the port of sshd every day according to some logic I will use on the
client side to find the port for that day. This script will run in
background and will do the job of modifying the config file and
restarting of the service automatically.

Does that sound like even more seure idea?

Regards from
Vijay Gill