NAG decoded using image reconstruction

[watchnit]

Analysis of the Nagravision Video Scrambling Method
(Original Abstract - August 23, 1998 - University of Cambridge)
Abstract: The Kudelski Nagravision pay-TV conditional access system can be practically broken by image processing algorithms that rearrange the lines of a field based on statistical properties of typical TV images.

With some knowledge about the limitations of the scrambling hardware one can reconstruct the scrambled TV image in real-time without knowledge of the cryptographic secret stored in the subscriber smart card. (By Markus G. Kuhn)


See attachment for details

[watchnit]

NO attachment in last post... sorry folks... file is PDF and this site does not allow PDF... or ZIP or RAR... Guess we are SOL... .

[McLovin]

google the title to see the pdf. after reading the paper, it describes a process for descrambling an analog tv signal. doesn't apply to charlie.

[Zerokill]

This is VERY OLD technology that you are referencing.....the difference between cracking an analog system versus a digital one is infitessimal.

That PDF has nothing to do with current encryption standards or methods.

.ZK.

[watchnit]

I am not sure that digital versus Analog is of any issue... when I read the article, I get the impression that subsequent frames are determined from patterns in the first set of frames... an MPEG sequence would even be easier since B and P frames already contain data about preceeding and following frames... where as in analog, each frame is a complete frame... Take the digital aspects of an I frame in MPEG and comparing that to the analog signals that it produces in a composite video signal is not rocket science... without encryption, that translates well... in fact... any mathematical expression of an analog signal would need to be digitized first anyways...

As for the encryption, the idea that one can determine what the next frames should be from video patterns in the picture, would seem to make sense and hold water across any encryption scheme... its really finding the initial references that seems difficult

On a side note... this type of technology was used in the late 90s for coloring B&W films... the frames were processed into digital and by simply tapping on an image in one frame, the S/W was smart enough to follow that image (with changes like arm movements etc..) across several 1000s of frames provided the image did not leave the scene... ( I worked on this technology during school... and wrote a paper on it in 1984 )

[Birdie]

A+ for trying. it is all digital so this does not help.
I do thank you though as all the posts are important.

[gun smoke]

A+ for trying. it is all digital so this does not help.
I do thank you though as all the posts are important.
don't mean to get off the subject,that purple card you use for your avatar ,is this the card of the future.Thanks
http://www.dssftp.com/forum/image.php?u=44780&dateline=1229926865

[Zerokill]

I am not sure that digital versus Analog is of any issue... when I read the article, I get the impression that subsequent frames are determined from patterns in the first set of frames... an MPEG sequence would even be easier since B and P frames already contain data about preceeding and following frames... where as in analog, each frame is a complete frame... Take the digital aspects of an I frame in MPEG and comparing that to the analog signals that it produces in a composite video signal is not rocket science... without encryption, that translates well... in fact... any mathematical expression of an analog signal would need to be digitized first anyways...

As for the encryption, the idea that one can determine what the next frames should be from video patterns in the picture, would seem to make sense and hold water across any encryption scheme... its really finding the initial references that seems difficult

On a side note... this type of technology was used in the late 90s for coloring B&W films... the frames were processed into digital and by simply tapping on an image in one frame, the S/W was smart enough to follow that image (with changes like arm movements etc..) across several 1000s of frames provided the image did not leave the scene... ( I worked on this technology during school... and wrote a paper on it in 1984 )


Nagravision uses digital encryption based on the DES standard. While the DES standard has been "cracked", it's not as easy as you think to derive the proper sequencing keys and reorder the video signal.

About 20 years ago, most encryption was based on Macrovision and frame manipulation encryption methods. These were all analog and were pretty easy to defeat with screen grabber or MacroVision scrubber circuits.

The modern day of digital encryption is a LOT more than retiming of the NTSC standard.
The entire picture is resequenced and compressed and THEN encrypted using a 56, 128, or 256 bit key. In the datastream there is also authorization flags intended for particular smartcards. Once your smartcard has been enabled with these authorization flags, it allows the viewing of the channels you have paid for (after it does it's math).

The current method of hacking N2 is the manipulation of the keys because the smartcard has been comromised and the routines are known (it has been "dumped").

There has not yet been any "joy" on the N3 as of yet in regards to dumping the smartcard. There are; however; devices available that grab the "results" of the smartcard AFTER the decryption has taken place and routes the authorization flag (control word) to another receiver that uses the authorization flag to watch TV. While not technically a hack or crack, it has (evidently) proven to work.

.ZK.

[Zerokill]

don't mean to get off the subject,that purple card you use for your avatar ,is this the card of the future.Thanks
http://www.dssftp.com/forum/image.php?u=44780&dateline=1229926865


Yes, that is the "G3" card (also known as the H02 or the N3 card) currently in deployment by DN.

.ZK.

[rg6a]

Perhaps we should report this Spammer to eBay?