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Thanks for the detailed description. > .. which passes it encrypted via HDCP2 to the monitor. And where does the decryption actually takes place? > EDIT htt

Thanks for the detailed description. > .. which passes it encrypted via HDCP2 to the monitor. And where does the decryption actually takes place? > EDIT https://en.wikipedia.org/wiki/High-bandwidth_Digital_Content_Protection https://en.wikipedia.org/wiki/High-bandwidth_Digital_Content... > In order to make a device that plays HDCP-enabled work, the manufacturer must obtain a license from Intel subsidiary Digital Content Protection LLC, pay an annual fee, and submit to various conditions.[5][6][7] For example, the device cannot be designed to copy; it must "frustrate attempts to defeat the content protection requirements";[7] it must not transmit high definition protected video to non-HDCP receivers; and DVD-Audio works can be played only at CD-audio quality[7] by non-HDCP digital audio outputs (analog audio outputs have no quality limits). This sounds quite far-fetched though. I'm quite sure we're going to see people literally recording their TV screen with a hand-camera soon. How about the case where the hardware doesn't support it. Would screen-grabbing be possible then? Where will the decryption take place in that case?

kevin_b_er 9y ago
> How about the case where the hardware doesn't support it. Would screen-grabbing be possible then? Where will the decryption take place in that case? You don't get the content then. Full stop.
- gsnedders 9y ago
  With many providers, you do still get the content, just limited to 480p.
the8472 9y ago
> How about the case where the hardware doesn't support it. Would screen-grabbing be possible then? Where will the decryption take place in that case? There essentially are several tiers of DRM - hardware-assisted encrypted pipelines (described above) - kernel module assisted - pure userspace obfuscated code If it's in userspace, such as some software DVD players or game DRM then you can use a debugger to dump the keys or maybe hook some method that sends the frames to the gfx card. If it's kernel-assisted you would have to bypass kernel module signing and hook deep into the operating system because the OS will also prevent screengrabbing of the protected surface. If it is hardware assisted you will have to find a flaw somewhere in the pipeline or buy devices that contain decryption chips that basically are repurposed official decryption chips.

kevin_b_er 9y ago

> How about the case where the hardware doesn't support it. Would screen-grabbing be possible then? Where will the decryption take place in that case? You don't get the content then. Full stop.

gsnedders 9y ago
With many providers, you do still get the content, just limited to 480p.

the8472 9y ago

> How about the case where the hardware doesn't support it. Would screen-grabbing be possible then? Where will the decryption take place in that case? There essentially are several tiers of DRM - hardware-assisted encrypted pipelines (described above) - kernel module assisted - pure userspace obfuscated code If it's in userspace, such as some software DVD players or game DRM then you can use a debugger to dump the keys or maybe hook some method that sends the frames to the gfx card. If it's kernel-assisted you would have to bypass kernel module signing and hook deep into the operating system because the OS will also prevent screengrabbing of the protected surface. If it is hardware assisted you will have to find a flaw somewhere in the pipeline or buy devices that contain decryption chips that basically are repurposed official decryption chips.