So in this scenario, what is the “decryption module” likely to be? Software you download? Software that comes with the OS? Hardware baked into the chip or mothe

So in this scenario, what is the “decryption module” likely to be? Software you download? Software that comes with the OS? Hardware baked into the chip or motherboard? What would prevent determined users from reading, and publishing, any “secret” keys used by such a decryption module? I'm assuming the answer is nothing, since this seems to have happened with every DRM scheme that has been tried.