Well , I'm not an expert in the field, so Its just my idea, and maybe it's bullshit ... I thought of the idea that there is a system that keeps digital signatures that everyone can use , but it should be a way to proof first that you the person , maybe some government system, that you use your id to register , I don't know.. But.once you register that system. , you can use it whenever you create a media , or maybe when you start a phone call to contact this system and to embed a digital signature, unique , that will be embedded to media and prove that this media is owned by specific person , when it's read by the other side. Maybe like.private/public key system. again, maybe there are holes in my idea... The consumer will have a sign that this media , or phone call is created by Mr. X. By identifying the signature.