It's illegal to have this number on your blog

Hexadecimal 09 F9 11 02 9D 74 E3 5B D8 41 56 C5 63 56 88 C0

This is the decryption key for most of the HD-DVD titles that have been released. Apparently the bigwigs in the entertainment industry are going after websites and blogs that host it. This is similar to what happened a few years ago when DeCSS was discovered. Some people were arrested for spreading the code for that one around (in quite a few creative ways). Just for the heck of it, here's one of DeCSS's smaller C implementations:

/*     efdtt.c     Author:  Charles M. Hannum              */
/*                                                                         */
/*     Thanks to Phil Carmody  for additional tweaks.    */
/*                                                                         */
/*     Length:  434 bytes (excluding unnecessary newlines)                 */
/*                                                                         */
/*     Usage is:  cat title-key scrambled.vob | efdtt >clear.vob           */

#define m(i)(x[i]^s[i+84])<<
unsigned char x[5],y,s[2048];main(n){for(read(0,x,5);read(0,s,n=2048);write(1,s
,n))if(s[y=s[13]%8+20]/16%4==1){int i=m(1)17^256+m(0)8,k=m(2)0,j=m(4)17^m(3)9^k
*2-k%8^8,a=0,c=26;for(s[y]-=16;--c;j*=2)a=a*2^i&1,i=i/2^j&1<<24;for(j=127;++j;c=c>y)c+=y=i^i/8^i>>4^i>>12,i=i>>8^y<<17,a^=a>>14,y=a^a*8^a<<6,a=a>>8^y<<9,k=s
[j],k="7Wo~'G_\216"[k&7]+2^"cr3sfw6v;*k+>/n."[k>>4]*2^k*257/8,s[j]=k^(k&k*2&34)
*6^c+~y;}}

But what would have happened if DVD encryption hadn't been cracked? It had mostly been an effort so that Linux users could use DVDs on their systems, because the industry had up to that point refused to support DVD on Linux. Would there have been the boom in do-it-yourself DVD recording that we now enjoy had the algorithm not been broken? Probably not.

Let's face it: for whatever intent they have, hackers do almost invariably do a great long-term service for us. They open up new technology, and they challenge hardware and software producers to constantly improve the products they pitch to us. Same thing is going to happen with high-def DVD content getting cracked: my bet is that it'll eventually make self-production of 1080p discs at home that much more viable.

Categories: decryption, DeCSS, DVD, encryption, HD-DVD, hex code, horse is out of the barn