GateWay folder is used for Device, which drives PYTHON enviroment, such as RASHBERRY PI, JETSONNANO, and Your PC
go to .gateway/main.py on line 73, the received frame will be simply decode. You can implement the decrypt methods in there.
udp_client folder include soure code which you can flash to ESP32-CAMERA.
Briefly, It takes a photo and send to gateway via WIFI local, using UDP.
In order to encrypt the data sending, follow the folder .udp_client/main/udp_client.c , on line 102.
camera_fb_t *pic = esp_camera_fb_get();
the data of picture is stored in pic->buf with pic->len indicate the length of picture in byte.