Microsoft puts DRM in P2P
p2pnet news view P2P | DRM:- Trust Microsoft to try to make money out of an oxymoron. Because that’s what putting DRM in the same sentence as P2P amounts to.
Steve and the Boyz reckon they’ve found a way to use DRM on P2P networks to distribute commercial media online.
It “works like a standard torrent network,” says Cryptopatents. When a user wants the content, “his machine grabs a list of the nearest peers and what parts of the content they have,” it says, going on, “The user downloads the individual pieces and the file is reassembled on his computer.”
But, Microsoft’s twist is to lock each packet using “several layers of encryption: public key cryptography, DES and RC4 for the algorithm’s different components,” says the story, going on >>>
In an ideal setting, the scheme works like this: Microsoft sends you a master key that has been enciphered with your public key. You decrypt the master key and the result is hashed using SHA. The output is split in two, with the first part used as the root of the machine authentication code key (MAC, similar to a checksum), the second is the DES key. The DES key is used to decrypt the RC4 content key that, in turn, is used to decrypt the content payload. The whole thing is XOR’d with the MAC and the output is reassembled for your viewing pleasure.
Under “Digital rights management scheme for an on-demand distributed streaming system,” and listing Jin Li and Yi Cui as the inventors, the Microsoft P2P DRM “may be optionally invoked by the owner,” says the abstract to patent application 10934823, adding >>>
With the DRM protection turned on, the media is encrypted before it is distributed in a P2P network, and is decrypted prior to its use (play back). The peers may still efficiently distribute and serve without authorization from the owner. Nevertheless, when the media is used (played back), the client node must seek proper authorization from the owner. The invention further provides a hierarchical DRM scheme wherein each packet of the media is associated with a different protection level. In the hierarchical DRM scheme of the invention there is usually an order of the protection level. As a result, in one embodiment of the invention, the decryption key of a lower protection layer is the hash of the decryption key at the higher protection level. That way, a user granted access to the high protection layer may simply hold a single license of that layer, and obtain decryption keys of that layer and below. The invention further provides for a process for managing digital rights to a scalable media file wherein a different encryption/decryption key is used to encrypt each truncatable media packet with a base layer without requiring additional storage space to store the key.
DRM is a dead horse. But they never give up, do they?
(Cheers, RW)
..… and identi.ca
First they ignore you, then they laugh at you, then they fight you, then you win ~ Mahatma Gandhi
Cryptopatents – Microsoft Patents P2P DRM Methods, January 4, 2010
Use free p2pnet newsfeeds for your site. Subscribe to p2pnet.net | | rss feed: http://p2pnet.net/feed
Net access blocked by government restrictions? Use Psiphon from the Citizen Lab at the University of Toronto. Go here for details.
January 9th, 2010 at 11:54 pm
This is the exact equivalent of taking a DRM protected file such as a locked wma or wmv and sharing it via a torrent. To play it back, you still need a machine-specific key, but anyone can distribute the original DRM encrypted file. The only novel idea in this patent is a system to use the DRM MAC as a component in the peer connection encryption, which doesn’t really have much benefit over a standard ModExp key exchange + symmetric cypher as far as security goes. I suppose it would make a man-in-the-middle attack slightly less practical.
These utility patents that the software corporations are gobbling up REALLY shouldn’t be granted. They are way too obvious / simple and it’s pretty likely there’s ‘prior art’ that has come and gone several times over the years. This reminds me of the TrueNames patent fiasco where they say accessing anything over a network via any sort of hash or checksum infringes on their patent. The problem is, these flimsy patents get used to hammer potential competition into the ground via frivolous legal actions designed to drain the money from any startups that move in on the big corp’s turf. It was real nice getting legal demands from BDE-Altnet and coughing up cash for an experienced patent attorney when we barely had the cash to pay for our bandwidth bill. (We ended up just ignoring them though, and nothing happened.)
January 10th, 2010 at 2:05 am
“These utility patents that the software corporations are gobbling up REALLY shouldn’t be granted.”
Since when has the patent office denied a patent for any reason? Some patent trolling corp. probably has a patent on a warp drive and transporter. It used to be in the days of Edison you actually had to be building whatever you took a patent out on. Now you can patent whatever ideas come into your head, and then squeeze a real inventor for money if one of the ideas actually gets invented. Total bullshit.
January 11th, 2010 at 6:01 am
The patent office is not doing it’s job granting all these BS rubbish patents of very obvious stuff and gillions of prior arts.
Our government is entirety in the pocket of few big corporations such as Microslosh.
Extreme capitalism without rule is like communism save that instead of having one huge government you have few corporate monster who control everything.
In both case there is no individual freedom and the possibility to conduct business is seriously diminished.
We have to destroy these few big corporations by any mean before they destroy our societies and possibly the planet.
Let’s start with the entertainment industry and follow up by the banks.
January 11th, 2010 at 6:09 am
We ended up just ignoring them though, and nothing happened.)
That’s a good strategy.
However the sad thing is that if something happen it is better to just pay a killer which is a lot shipper and way faster than an attorney to solve this type of problem.
January 12th, 2010 at 3:05 pm
I love Cryptography but that made my head hurt lol
February 17th, 2010 at 1:51 am
Anyone could just find another non-protected torrent.