Page 99 - DCAP309_INFORMATION_SECURITY_AND_PRIVACY

Unit 7: Network Security

Notes
Example: One company participating in an extranet might be using Microsoft Internet
Explorer, another Netscape Navigator 4.5, and another Navigator Gold 3.x.
In order to collaborate via extranet, the applications have to perform adequately on all represented
platforms. The same is true for e-commerce, in which the trading partners may be completely
unknown to one another. This is the case when we walk into a supermarket: the common
interest in communication is based on the need to transact business, and not necessarily on a
long-term trust relationship. Thus e-commerce applications often support a level of security and
transactional integrity not present in intranet or extranet applications.

Self Assessment

Fill in the blanks:
3. All local area networks transfer data in ................. form at a high speed and have a low
implementation cost.

4. Wide Area Networks are also referred to as ................. .
5. ................. is a global network of networks connecting many millions of computers.
6. A ................. is a private network provider that is hired by a company to facilitate electronic
data interchange (EDI) or provide other network services.

7.3 Basic Concepts

Here we will discuss the concept of computer security and network security.

7.3.1 Computer Security

Securing network infrastructure is like securing possible entry points of attacks on a country by
deploying appropriate defense. Computer security is more like providing means to protect a
single PC against outside intrusion. The former is better and practical to protect the civilians
from getting exposed to the attacks.
The preventive measures attempt to secure the access to individual computers – the network
itself – thereby protecting the computers and other shared resources such as printers, network-
attached storage connected by the network. Attacks could be stopped at their entry points before
they spread. As opposed to this, in computer security the measures taken are focused on securing
individual computer hosts.
A computer host whose security is compromised is likely to infect other hosts connected to a
potentially unsecured network.

Did u know? A computer host’s security is vulnerable to users with higher access privileges
to those hosts.

7.3.2 Network Security

Attributes of a Secure Network

Network security starts from authenticating any user, most likely a username and a password.
Once authenticated, a stateful firewall enforces access policies such as what services are allowed

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