Unless app allows you to have encrypted line for the video data transfer there is no way you can have secure video chat.
If you want to have secure video chat then I suggest you to subscribe to some VPN network. And once you use that VPN service you can get alternative IP and security for your video chat or any form of chat for that reason.
If you want messaging security then you can use Telegram too. Telegram is secure for the messaging. You can have encrypted messages to send. Other than that if you want security for every communication you do, the best way is using Tor and also the VPN extensions.