Operating systems use protection and security techniques to counter threats to information. Protection involves guarding a user's data and programs from interference by other authorized users, while security guards against interference from unauthorized external entities. There are two facets to protection: secrecy, where only authorized users can access information, and privacy, where information is only used for its intended purpose. Security and protection policies are enforced through mechanisms like access control lists and authentication. The goals of security and protection are secrecy, privacy, authenticity, and integrity of information.
2. Introduction
Interference in resource utilization is a
very serious threat in an OS
The nature of the threat depends on the
nature of a resource and the manner in
which it is used.
3. Protection and Security
OS use two sets of techniques to
counter threats to information namely:
Protection
Security
5. Security
It involves guarding of a user’s data
and programs against interference by
external entities, e.g. unauthorized
persons.
6. Facets to protection of information
There are two facets to protection of
information
Secrecy: Implies that only authorized users
should be able to access information.
Privacy: Implies that information should be
used only for the purpose(s) for which it is
intended and shared.
7. Security and Protection: Policies and Mechanisms
Security:
Specify whether a person can
become a user of the system.
This function is performed by
the system administrator
Add or delete
users.
Verify whether a
person is an
authorized user.
Mechanisms:
Policy:
1.
2.
8. Protection:
Policy:
Mechanisms:
Specify whether a user can
access a specific file. The
owner of a file performs this
function while creating it.
Set or change protection
information for a file.
Check whether a file can
be accessed by a user.
2.
1.
9. Security Threats
Direct: This is any direct attack on your
specific systems, whether from outside
hackers or from disgruntled insiders.
Indirect: This is general random attack,
most commonly computer viruses,
computer worms or Trojan horses.
10. Reasons for taking Security measures
To prevent loss of data
To prevent corruption of data
To prevent compromise of data
TO prevent theft of data
To prevent sabotage
11. GOALS OF SECURITY AND PROTECTION
Secrecy: Only authorized user should be able to access
information.
Privacy: Information should be used only for the purpose for
which it was intended and shared.
Authenticity: It should be possible to verify the source or
sender of the information and also verify the information has been
preserved in the form in which it was created or sent.
Integrity: It should not be possible to destroy or corrupt the
information .
12. AUTHENTICATION
Goal of Authentication: Reasonable assurance
that anyone who attempts to access a system
or a network is a legitimate user.
2 Mechanisms:
Password
Biometric measure
13. Authentication using Biometrics
Use basic body properties to prove identity.
Examples include:
Fingerprints
voice
Hand size
Retina patterns
Facial features