参见：
http://www.microsoft.com/china/technet/security/guidance/clientsecurity/dataencryption/analysis/4e6ce820-fcac-495a-9f23-73d65d846638.mspx#EOD
Tuomas Aura在APTISS上讲述bitlocker driver encryption技术的ppt
http://blogimg.chinaunix.net/blog/upfile/070904110728.rar