Comments on: What’s so “special” about CSS DVD encryption data that makes it “not authorable” onto DVD-R-general or DVD+R? http://www.petersonalarm.com/whats-so-special-about-css-dvd-encryption-data-that-makes-it-not-authorable-onto-dvd-r-general-or-dvdr.php Personal Home Alarms & Security System Information Sun, 14 Mar 2010 22:59:45 +0000 http://wordpress.org/?v=2.7.1 hourly 1 By: Good Daddy http://www.petersonalarm.com/whats-so-special-about-css-dvd-encryption-data-that-makes-it-not-authorable-onto-dvd-r-general-or-dvdr.php/comment-page-1#comment-13975 Good Daddy Wed, 17 Jun 2009 11:17:22 +0000 http://www.petersonalarm.com/whats-so-special-about-css-dvd-encryption-data-that-makes-it-not-authorable-onto-dvd-r-general-or-dvdr.php#comment-13975 the answer is actually very simple. If i were to make a DVD drive, i would by law have to follow the DVD Content Scramble System (css) key standards set forth by the DVD Copy Control Association. Meaning that my dvd drive would have to read the lead-in area of a DVD disk (where the security keys are present) and subsequently decide if the user (being software or human) has sufficient access to the data on the rest of the disk. Luckily the CSS encryption algorithm was compromised (fairly easily) using the DeCSS method. All it does is tell the dvd drive to ignore the lead-in keys by deriving a master security key exploit. an example of a DeCSS enabled software package is DVDShrink. Obviously this software is for "edicational" purposes only and can not be sold due to copyright infringement on owners of the CSS encrypted data it may or may-not be used on. Here's a snippet of the DeCSS algorithm: http://upload.wikimedia.org/wikipedia/commons/a/a9/DeCSS.PNG Now a better question is the state of HD disk encryption cracking. much more complicated, but also compromised as of now. EDIT: K, let me do some research, but i believe the General purpose DVD's don't have an area for lead-in data. I'll get back to ya about that, but i've never come accross that problem. do you have documentation that the problem even exists (like posts from other people with the same problem) and maybe not a fluke in just your current hardware set? EDIT AGAIN: LOL! thx merc. http://shop.cafepress.com/item/black-t-shirt/46724397?cmp=pfc--f--us--152--46724397&utm_source=froogle&utm_medium=pr EDIT YET AGAIN: Couldn't come up with any definitive answer, but i believe i've never come across this problem (if it does indeed exist) simply because i've never copied CSS data. I always strip it, along with the region code, when backing up my dvd collection. the answer is actually very simple. If i were to make a DVD drive, i would by law have to follow the DVD Content Scramble System (css) key standards set forth by the DVD Copy Control Association. Meaning that my dvd drive would have to read the lead-in area of a DVD disk (where the security keys are present) and subsequently decide if the user (being software or human) has sufficient access to the data on the rest of the disk.

Luckily the CSS encryption algorithm was compromised (fairly easily) using the DeCSS method. All it does is tell the dvd drive to ignore the lead-in keys by deriving a master security key exploit. an example of a DeCSS enabled software package is DVDShrink. Obviously this software is for "edicational" purposes only and can not be sold due to copyright infringement on owners of the CSS encrypted data it may or may-not be used on. Here's a snippet of the DeCSS algorithm:
http://upload.wikimedia.org/wikipedia/commons/a/a9/DeCSS.PNG

Now a better question is the state of HD disk encryption cracking. much more complicated, but also compromised as of now.

EDIT:
K, let me do some research, but i believe the General purpose DVD's don't have an area for lead-in data. I'll get back to ya about that, but i've never come accross that problem. do you have documentation that the problem even exists (like posts from other people with the same problem) and maybe not a fluke in just your current hardware set?

EDIT AGAIN:
LOL! thx merc.
http://shop.cafepress.com/item/black-t-shirt/46724397?cmp=pfc–f–us–152–46724397&utm_source=froogle&utm_medium=pr

EDIT YET AGAIN:
Couldn't come up with any definitive answer, but i believe i've never come across this problem (if it does indeed exist) simply because i've never copied CSS data. I always strip it, along with the region code, when backing up my dvd collection.

]]> By: Mercuri http://www.petersonalarm.com/whats-so-special-about-css-dvd-encryption-data-that-makes-it-not-authorable-onto-dvd-r-general-or-dvdr.php/comment-page-1#comment-13976 Mercuri Wed, 17 Jun 2009 11:17:22 +0000 http://www.petersonalarm.com/whats-so-special-about-css-dvd-encryption-data-that-makes-it-not-authorable-onto-dvd-r-general-or-dvdr.php#comment-13976 Well, the CSS copy protection acts like a decoder ring for those 0s and 1s. You can just copy the 0s and 1s directly, but it'll all be jumbled up and wouldn't make any sense. However, CSS copy protection is an easily breakable protection scheme. I won't tell you how to do this (because it's illegal to break the CSS) but there were even T-shits with the source code for the program to break the protection. Not that you would know, but to have the code for that program be short enough to fit in a t-shirt is something ridiculous. Well, the CSS copy protection acts like a decoder ring for those 0s and 1s. You can just copy the 0s and 1s directly, but it’ll all be jumbled up and wouldn’t make any sense. However, CSS copy protection is an easily breakable protection scheme. I won’t tell you how to do this (because it’s illegal to break the CSS) but there were even T-shits with the source code for the program to break the protection. Not that you would know, but to have the code for that program be short enough to fit in a t-shirt is something ridiculous.

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