COMPUTER NETWORK SECURITY PART 4
Back again in the
network security article we just discussed for part 4
IV.
In
general, security can be categorized into two types: prevention (preventive)
and treatment (recovery). Prevention efforts are done so that the information
system does not have a security hole, while the treatment efforts are done if
the security hole has been exploited. Setting Access (Access Control). One
common way used to secure information is to regulate access to information
through the mechanism of "authentication" and "access
control".
Implementation
of this mechanism is by using "password". Unused Service Closing
Often systems (hardware and / or software) are provided with some services
running as default. For example, in UNIX systems the following services are
often installed from the vendor: finger, telnet, ftp, smtp, pop, echo, and so
on. Not all services are needed. To secure the system, unnecessary services on
the server (computer) should be turned off. Install Protection. To further
enhance the security of information systems, protection can be added. This
protection can be a filter (in general) and more specifically a firewall.
Filters can be used to filter e-mail, information, access, or even within the
packet level.FirewallFirewall is a device that is placed between the Internet
and the internal network.Information coming out or incoming must go through
this firewall. The main purpose of a firewall is to keep (prevent) access to
(unauthorized access) from unauthorized persons. Monitoring of attacks.
Monitoring
system (monitoring system) is used to determine the presence of uninvited
guests (intruder) or the attack (attack). Another name of this system is the
"intruder detection system" (IDS). This system can notify
administrators via e-mail or through other mechanisms such as through pager.
System integrity monitor The system integrity monitor is run periodically to
test the system integrity. One example of a program commonly used in UNIX
systems is the Tripwire program. The Tripwire package program can be used to
monitor changes to the file. Audit: Observing Logs Files All (most) system
usage events can be recorded in files that are usually called
"logfile" or "log" only. This log file is useful for
observing the deviations that occur. Failure to log into the system (login),
for example, is stored in the log file. For that the administrators are
required to diligently maintain and analyze log files ownedBackup routinelyBut
often intruder guests into the system and damage the system by removing the
files that can be found. If this intruder successfully breaks down the system
and logs in as a super administrator (administrator), then it is possible he
can delete the entire file. Use of Encryption to increase securityOne satau
mechanism to improve security is to use encryption technology.
The
data you submit is modified in such a way that it is not easily tapped. Many
services on the Internet still use "plain text" for authentication,
such as the use of a userid and password pair. This information can be viewed
easily by a bug or sniffer program. WWW Server Security The WWW server security
is usually an administrator issue. By installing a WWW server on your system,
you open access (though limited) to outsiders. If your server is connected to
the Internet and your WWW server is prepared for the public, then you should be
more careful because you open access doors around the world. Restrict access
through Access Control As a provider of information (in the form of files), it
is often desirable to restrict access . For example, it is desirable that only
certain people can access certain files (information).In principle this is the
problem of access control.Protection of pages by using passwordOne of the
mechanisms of regulating access is to use the userid pairs (user
identification) and password. For Apache-based Web servers [6], access to a
page (or set of files located in a directory on a Unix system) can be set using
the ".htaccess" file.
Knowing the Server Type Information about the
web server used can be exploited by the destroyer for launches attacks
according to the server type and operating system used. CGICommon Gateway
Interface (CGI) Program Security is used to connect WWW systems with other
software on the web server.The existence of CGI allows an interactive
relationship between the user and the web server. WWW client security In the
previous section discussed issues related to the WWW server. In this section
will be discussed issues related to security of WWW client, that is user
(visitor) usual. Security on the client side is usually associated with privacy
issues and the insertion of viruses or Trojan horses.
Set
access control
One common way to
secure information is to manage access to information through
"authentication" and "access control"
mechanisms.Implementation of this mechanism, among others, by using
"password".
Changing
User Properties
Click the Properties
button to view the properties of the user. There are 2 main options in addition
to the 8 group members selections:
1.
Standard User (Power User)
Users can change some
system files, install programs that have no effect on windows system files
2.
Restricted User (User Groups)
Users can use the
computer and save the document but can not install the program and change the
windows system settings.
User
Settings (continued)
Passwords and .NET
Passwords are used as a facility to manage user password data that can use
computer and email. Advanced user management is used to manage user groups and
users in more detail.
Password
creation criteria
- Do not use login
names, first or last names and their variations and names of spouses or children.
- Do not use other
easily available information about you like No tel, Date of Birth.
- Use a password that
is a combination of capital letters and lowercase letters and numbers.
- Use special "32
ALT characters", typed by holding the Alt key while typing numbers between
128 and 255 on the numeric keypad with the Num Lock on indicator.
- Use easy typed
passwords, without looking at the keyboard.
Closes
unused service
- Often systems
(hardware and / or software) are provided with some services run as default.
for example, on UNIX systems the following services are often installed from
the vendor: finger, telnet, ftp, smtp, pop, echo, and so on.
- The service is not
all needed. To secure the system, unnecessary services on the server (computer) should be turned off.
Installing
Protection
- To further improve
the security of information systems, protection can be added. This protection
can be a filter (in general) and more specifically a firewall. Filters can be
used to filter e-mail, information, access, or even packet level.
- For example, on UNIX
systems there is a "tcpwrapper" program package that can be used to
restrict access to certain services or applications. For example, a service for
"telnet" may be restricted to systems that have a certain IP number,
or have a specific domain.
- While firewalls can be
used to filter generally.