Posted 07 September 2009 - 02:42 PM
NTFS is only a filesystem, but it implements permissions at the same time. It does this by means of an Access Control List (ACL) located in the Master File Table, which is basically the Table of Contents for an NTFS partition.
These ACLs are NTFS specific and cannot be applied to a partition or drive formatted in any other filesystem. Windows XP is designed to only be able to read NTFS and FAT filesystems anyway, and FAT does not have any provision for security or permissions whatsoever. In fact, copying a file from an NTFS drive to a FAT drive will strip all permissions from it.
NTFS ACL's may or may not be honored by other operating systems (such as Linux.) This is because enforcement of the ACL's is left to the operating system, even if the ACL's themselves are independent o the system. The same is not true for files encrypted using NTFS EFS, another feature of NTFS.