The purpose of DRM is to turn a mathematical impossibility into money.
I put a note that I want you to read and keep secret into a box. Then I lock the box. Then I tape the key to the lid of the box, attach a sticky note with specific instructions on how you are allowed to use the key and the note, and give the whole package to you. That's DRM.
You open the box with the key, copy the note, put the original back in the box, lock it again, burn the key, and send the box back. You still have the copy of the note. That's reality.
You cannot send a message to an untrusted person in a trusted way, no matter how many trusted lock boxes you use. The instant you make it readable to the recipient, it is copyable. Your only options are to either not send secrets to strangers, or to assume that anything you send to a stranger is no longer secret.
As they say, three can keep a secret if two of them are dead.
The true purpose of DRM is to raise the level of difficulty for copying above the median skill level of the recipients. That way, you can buy legislation to intimidate the smartest guys and limit the supply of copies. It is strictly to reduce the burden of law enforcement to a more manageable list of suspects, from "everyone on the planet" down to "anyone with a JTAG debugging workbench".
I put a note that I want you to read and keep secret into a box. Then I lock the box. Then I tape the key to the lid of the box, attach a sticky note with specific instructions on how you are allowed to use the key and the note, and give the whole package to you. That's DRM.
You open the box with the key, copy the note, put the original back in the box, lock it again, burn the key, and send the box back. You still have the copy of the note. That's reality.
You cannot send a message to an untrusted person in a trusted way, no matter how many trusted lock boxes you use. The instant you make it readable to the recipient, it is copyable. Your only options are to either not send secrets to strangers, or to assume that anything you send to a stranger is no longer secret.
As they say, three can keep a secret if two of them are dead.
The true purpose of DRM is to raise the level of difficulty for copying above the median skill level of the recipients. That way, you can buy legislation to intimidate the smartest guys and limit the supply of copies. It is strictly to reduce the burden of law enforcement to a more manageable list of suspects, from "everyone on the planet" down to "anyone with a JTAG debugging workbench".