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HDCP Encryption/Decryption Code Released
rtj writes "We have released an open-source (BSD licensed) implementation of the HDCP encryption/decryption algorithms. The code includes the block cipher, stream cipher, and hashing algorithms necessary to perform an HDCP handshake and to encrypt or decrypt video. The code passes the test vectors provided in the HDCP specification and can encrypt video at a rate of about 180 640x480 frames/second on a 2.33GHz Intel Xeon CPU. This isn't quite fast enough to decrypt 1080p content in real-time on a single core, but decryption can be parallelized across multiple cores. There are also many opportunities for further optimisation, such as using SSE instructions. We are releasing the code in hopes that others will further optimize it and use it in their HDCP-related projects."
Intel's statement had to do with the security of the use case of HDCP: digital video encrypted with HDCP being transported over HDMI cables. In other words, the hardware Intel claims is required, is specialized hardware which interfaces with HDMI ports. This software implementation is not interesting for cracking encrypted video if it cannot communicate with the Blu-Ray or other media player in question in a way which tricks the media player into thinking that the computer running the software is a certified display device.
I guess the next logical step would be a GPU implementation....
Errrrr the point of this software is to perform the handshake which authenticates it as a legitimate source or sink device. The master key also allows you to simply generate a NEW device key if the one you are using happens to get blacklisted by a firmware update.
The reason this is useful is not for bluray, it is for first-run broadcast content.
I think you greatly underestimate the advantage an ASIC has over a general purpose CPU (even the latest Intel CPUs with AES-NI) when it comes to crypto.
How about you RTFA:
"The HDCP cipher is designed to be efficient when implemented in hardware, but it is terribly inefficient in software, primarily because it makes extensive use of bit operations. Our implementation uses bit-slicing to achieve high speeds by exploiting bit-level parallelism. We have created a few high-level routines to make it as easy as possible to implement HDCP, as shown in the following example. "
retrorocket.o not found, launch anyway?
DRM must be really really costly. And the bad thing is we're all paying for it - the honest customers even more than the "pirates" against which it is supposed to protect.
When I see how much computing resources it takes just to en/decrypt a stream - OK it's a general purpose processor, not something dedicated - I am thinking of the cost of those resources in all the devices we have. After all your BluRay player has to read the BR disk, decrypt the content, then encrypt it again to an HDCP stream, which is sent over to say a TV, which then decrypts it again to make it a watchable image.
Now if only we wouldn't need that encryption.
BluRay itself is (all but) cracked, that's one decryption step that can be done away with.
HDCP transfer is now done with; that's another two steps of en- and decryption that can go.
That is at least three pieces of beefy hardware. That's three chips that won't come for a few pennies each. That's three chips that will be wasting significant amounts of energy.
Plus of course the huge upfront cost to develop all that: to develop the algorithms, set up the secure key supply, designing the dedicated de/encrypt chips and writing all the software around it to make it work.
And all of us are paying for it. It makes BR players and disks and HDCP compliant hardware more expensive than necessary, it even increases our power bills unnecessary. I really wonder when this madness can come to an end.