What is Content Scramble System?
The '''Content Scrambling System''' (or '''Content Scramble System''') is a system to [[encryption|encrypt]] and copy-protect [[DVD]]s. Such systems are generally called [[Digital Rights Management]] (or ''DRM'') systems. CSS uses [[symmetric cryptography]]. It was introduced in 1996; today, it is considered ineffective. In October 1999, [[Jon Lech Johansen]] and two other people (who remained anonymous) broke the system. CSS uses 40-bit cryptographic keys; because of different design problems, the effective key length is only about 16 bits. A 450 MHz processor, current at the time could [[Brute force attack|brute force crack]] this in less than a minute. A modern processor such as the [[Intel Core i7|Core i7]] or Athlon 64 can crack it in a few seconds. CSS requires special information in the lead-in (a special area) of the disc. Since the lead-in cannot be changed on recordable DVDs these cannot have CSS protection (with a few exceptions, some professional drives allow writing CSS keys to recordable discs). == Open source implementations == Libdvdcss is an open-source implementation used by many DVD software players, including [[VLC Media Player]]. Libdvdcss is region-free; it can read foreign-region DVDs even when the [[Key (cryptography)|keys]] can't be read from the drive, by using a brute-force attack. {{Tech-stub}} [[Category:Cryptography]] [[Category:DVD]]