Yes, all DRM systems are inherently impossible to make fully secure with only local data.<p>However, several other options exist:<p>* Needing to contact an external server to view an image (of course, you could always take the opportunity to save the now-viewable image then share it)<p>* Charging a large fee &#x2F; legal contracts for the information on how to decode (security through obscurity)<p>* Making circumvention illegal and enforcing this with fines or jail time. This is probably the only option that &quot;actually works&quot; as you&#x27;ve turned the technical problem into a social problem. People would still break it, but you could simply arrest them if they try to help others do the same.