DDNS simply allows you to be able to access your WAN if/when the IP address changes, but it doesn't do anything to secure your device. DDNS is used whether someone port forwards or uses a VNP.
Most here will agree that port forwarding directly to the camera is the least safe. Although the great internet has many articles that state it is OK lol like
whatismyipaddress.com that states:
"Port forwarding is an excellent way to preserve public IP addresses. It can protect servers and clients from unwanted access, "hide" the services and servers available on a network, and limit access to and from a network. Port forwarding is transparent to the end user and adds an extra layer of security to networks. In short, port forwarding is used to keep unwanted traffic off networks. It allows network administrators to use one IP address for all external communications on the Internet while dedicating multiple servers with different IPs and ports to the task internally. Port forwarding is useful for home network users who may wish to run a Web server or gaming server on one network."
Next are the other options. There is a debate as to if P2P (what Hik-Connect uses) or OpenVPN or something like ZeroTier is the next safer option.
Arguments are made both ways.
P2P you are relying on the camera manufacturer's servers to not be hacked. You have zero control over those. Dahua has recently been shutting down the older P2P servers that were more easily hacked.
Same with ZeroTier or Wireguard or Tailscale and the like. You are relying on someone else's servers to make that connection. Anytime you are relying on someone else, it can be
hacked.
OpenVPN is hosted locally, either native to the router or installed on a computer.
In theory you have the most control over this since it is all in your house.
But it relies on opensource coding that can be
hacked as well.
You are relying on your computer and router to be up to date and not allow bad actors in. And sadly, like NVRs and cameras, routers are not routinely updated either. But that is the same regardless of the solution you are using.
Or just say F it and use port forward and scanning QR codes blindly like most of society. At the end of the day, most don't get hacked. It just sucks if you are one of them that do.
At a bare minimum, set up a crazy strong password. Consider not using admin for the username - make a new username. Put the camera on a guest network so at the very least it doesn't exploit your entire network and connected devices, etc.