AES encryption in Evostream

Hi, We are trying aes encryption with HLS stream. Do we have some control over key created by evostream. Can we have our own key. Which AES encryption key length you are using internally eg 128bits,192bits etc One More Query >> when playing file in IE or any modern browser, on debugging using F12, user can easily access the key by copying the URL from network and thus have all the necessary information to decode that one. Can we restrict this one.. ie no one can allow to access the key.