How Do I Prevent Secondary Distribution After Audios and Videos Are Downloaded?

VOD provides HLS encryption. You can enable HLS encryption during transcoding. If this function is enabled, transcoded HLS videos will be encrypted. When end users request to play a video, you can verify user identity on the app server. Only verified users can obtain the decryption key and use the key to request VOD to decrypt and play the video. For details about HLS encryption, see Protecting Videos with HLS Encryption.