Network and Information System
Security
Module 1
MODULE – 1 : Fundamentals of Security
Definition of Security
Information Security
Topic-I Definitions and Challenges of Security
Computer Security
The protection afforded to an automated information
system in order to attain the applicable objectives of
preserving the Integrity, Availability, and
Confidentiality of Information System resources
(Information System resources includes hardware,
software, firmware, information/ data, and
telecommunications).
Security
Computer Security
Generic name for the collection of tools designed to
protect data and to thwart hackers
Network Security
Measures to protect data during their transmission
Internet Security (our focus!)
Measures to protect data during their transmission
over a collection of interconnected networks
Security Objectives
Security Objectives
Confidentiality
Preserving authorized restrictions on
information access and disclosure,
including means for protecting personal
privacy and proprietary information
A loss of confidentiality is the unauthorized
disclosure of information
Integrity
Protecting against improper information
modification or destruction including ensuring
information non repudiation and authenticity
A loss of integrity is the unauthorized
modification of destruction of information.
Availability
Ensuring timely and reliable access to and use of
information
A loss of availability is the disruption of access to
or use of information or an information system
Authenticity
The property of being genuine and being able to
be verified and trusted; confidence in the validity of
a transmission, a message, or message originator.
This means verifying that users are who they say
they are and that each input arriving at the system
came from a trusted source.
Accountability
Systems must keep records of their
activities to permit later forensic analysis
to trace security breaches or to aid in
transaction disputes
Security Breach Levels
High
The loss could be expected to have a severe or catastrophic
adverse effect on organizational operations, organizational
assets, or individuals
Moderate
The loss could be expected to have a serious adverse effect
on organizational operations, organizational assets, or
individuals
LOW
The loss could be expected to have a limited adverse effect on
organizational operations, organizational assets, or individuals
Security Challenges
Security is not simple
Potential attacks on the security features need to be considered
It is necessary to decide where to use the various security
mechanisms
Requires constant monitoring
Security mechanisms typically involve more than a particular
algorithm or protocol
Little benefit from security investment is perceived until a security
failure occurs
Strong security is often viewed as an im pediment to efficient
and user- friendly operation
