Novell LINUX ENTERPRISE DESKTOP 11, Manual, Page: 15 / 450

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Security and Confidentiality
One of the main characteristics of a Linux or UNIX system is its ability to handle sev-
eral users at the same time (multiuser) and to allow these users to perform several tasks
(multitasking) on the same computer simultaneously. Moreover, the operating system
is network transparent. The users often do not know whether the data and applications
they are using are provided locally from their machine or made available over the net-
work.
With the multiuser capability, the data of different users must be stored separately. Se-
curity and privacy need to be guaranteed. Data security was already an important issue,
even before computers could be linked through networks. Just like today, the most im-
portant concern was the ability to keep data available in spite of a lost or otherwise
damaged data medium, a hard disk in most cases.
This section is primarily focused on confidentiality issues and on ways to protect the
privacy of users, but it cannot be stressed enough that a comprehensive security concept
should always include procedures to have a regularly updated, workable, and tested
backup in place. Without this, you could have a very hard time getting your data
back—not only in the case of some hardware defect, but also if the suspicion arises that
someone has gained unauthorized access and tampered with files.
Security and Confidentiality 1