network security

1. MODULE 1

2. Introduction to network Security
 Computer data often travels from one
computer to another, leaving the
safety of its protected physical
surroundings.
 Cryptography can reformat and
transform our data, making it safer on
its trip between computers.

3. Introduction to network 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 - measures to
protect data during their transmission
over a collection of interconnected
networks

4. Introduction to network Security
 Network security is a level of guarantee
that all the machines in a network are
working optimally and the users of these
machines only possess the rights that
were granted to them
This can Include :
1. Preventing unauthorized people from
acting on the system maliciously
2. Preventing users from performing
involuntary operations that are capable
of harming the system
3. Securing data by anticipating failures

5. Introduction to network Security
Advantages of Network security
 Network security helps in protecting
personal data of clients existing on
network.
 Network security facilitates protection
of information that is shared between
computers on the network
 Hacking attempts or virus attacks from
the internet will not be able to harm
physical computers.

6. Security Requirements
The classification of security services are
as follows:
Confidentiality:
 The principle of confidentiality specifies
that only the sender and the intended
recipient should be able to access the
content of the message
 Eg: a credit card transaction on the
internet
Integrity:
 Integrity means that data cannot be
modified with out authorization.

7. Security Requirements
Availability:
 Requires that computer system assets
be available to authorized parties
when needed.
Authentication:
 Ensures that the origin of a message
or electronic document is correctly
identified, with an assurance that the
identity is not false.

8. Challenges of Security
 Security is not simple it requires a lot of
research and money
 Potential attacks on the security features
need to be considered.
 Procedures used to provide particular
services are often counter-intuitive.
 It is necessary to decide where to use the
various security mechanisms.
 Requires constant monitoring.

9. Challenges of Security
 Security mechanisms typically involve more
than a particular algorithm or protocol.
 Security is essentially a battle of wits
between a perpetrator and the designer.
 Little benefit from security investment is
perceived until a security failure occurs.
 Strong security is often viewed as an
impediment to efficient and user-friendly
operation.

10. Network Security Model
 Security aspects come into play when it is
necessary or desirable to protect the
information transmission from an opponent
who may present a threat to confidentiality,
authenticity, and so on. All the techniques for
providing security have two components:
 A security-related transformation on the
information to be sent.
 Examples include the encryption of the
message, which scrambles the message so
that it is unreadable by the opponent, and the
addition of a code based on the contents of the
message, which can be used to verify the
identity of the sender.

11. Network Security Model
 Some secret information shared by
the two principals and, it is hoped,
unknown to the opponent. An example
is an encryption key used in
conjunction with the transformation to
scramble the message before
transmission and unscramble it on
reception.

12. Network Security Model
 A trusted third party may be needed to
achieve secure transmission. For
example, a third party may be
responsible for distributing the secret
information to the two principals while
keeping it from any opponent.
 This general model shows that there
are four basic tasks in designing a
particular security service:

13. Network Security Model
1. Design an algorithm for performing the
security-related transformation. The
algorithm should be such that an
opponent cannot defeat its purpose.
2. Generate the secret information to be
used with the algorithm.
3. Develop methods for the distribution
and sharing of the secret information.
4. Specify a protocol to be used by the
two principals that makes use of the
security algorithm and the secret
information to achieve a particular
security service.

14. Network Security Model

15. Network Security Model
 Another type of unwanted access is the
placement in a computer system of logic that
exploits vulnerabilities in the system and that
can affect application programs as well as
utility programs, such as editors and
compilers. Programs can present two kinds of
threats:
1. Information access threats: Intercept or
modify data on behalf of users who should
not have access to that data.
2. Service threats: Exploit service flaws in
computers to inhibit use by legitimate users.

16. Intrusion Detection
Systems(IDS)

17. Thank You