Computer Security : Security Measure

Security measures mean the precautionary measures taken toward possible danger or damage. There are 6 types of security measures.

1) DATA BACKUP

Data Backup is a program of file duplication. Backups of data applications are necessary so that they can be recovered in case of an emergency.

Depending on the importance of the information, daily, weekly or biweekly backups from a hard disk can be performed.

2) CRYPTOGRAPHY

Cryptography is a process of hiding information by altering the actual information into different representation, for example, an APA can be

written as I? X.  

Almost all cryptosystems depend on a key such as a

password like the numbers or a phrase that can be used to encrypt or decrypt a message.

The traditional type of cryptosystem used on a computer network is called a symmetric secret key system.

3) ANTIVIRUS

An antivirus program protects a computer against viruses by identifying and removing any computer viruses found in the computer memory, on

storage media or incoming e-mail files.

An antivirus program scans for programs that attempt to modify the boot program, the operating system and other programs that normally are read from but not modified.

IDENTIFYING VIRUS

Two techniques are used to identify the virus.

VIRUS SIGNATURE	INOCULATING A PROGRAM FILE
Also called a virus definition is a specific pattern of the virus code.	The antivirus program records information such as the file size and file creation date in a separate inoculation file. The antivirus program then uses this information to detect if a virus tampers with the data describing the inoculated program file.

If an antivirus program identifies an infected file, it attempts to remove its virus, worm or Trojan horse. If the antivirus program cannot remove the infection, it often quarantines the infected file. Quarantine is a separate

area of a hard disk that holds the infected file until the infection can be removed. This step ensures other files will not become infected. Patents for inventions utility, design or plant patents that protect inventions and improvements to existing inventions

4) ANTI-SPYWARE

Spyware is a program placed on a computer without the user’s knowledge. It secretly collects information about the user.

The spyware program communicates information to

the outside source.

An anti-spyware application program sometime called tracking software or a spybot is used to remove spyware.

Among of the popular anti-spyware programs are:

  • Spybot Search and Destroy

  • Ad-aware

  • Spyware Blaster

5) FIREWALL

Firewall is a piece of hardware or software which functions in a networked environment to prevent some communications forbidden by the security

policy.

Firewall implements a security policy. It might permit limited access from in or outside the network perimeters or from certain user or for certain activities.

6) HUMAN ASPECTS OF SECURITY MEASURES

Human aspects refer to the user and also the intruder of a computer system.

It is one of the hardest aspects to give protection to.

The most common problem is the lack of achieving a good information security procedure.

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SECURITY PROCEDURES

Computers should have alarm systems to guard them from any attacks such as viruses and data corruption. The alarm system is the security measures that we take to ensure its safety.

DATA PROTECTION

We need to protect the data in the computer as it may somehow get lost or corrupted due to some viruses or mishap like fire, flood, lightning, and machine failures and even human errors.

There are a few ways to protect the information namely:

   • make backup files

   • detect the virus and clean the computer

   • warn others on virus attacks

1) BACKUP FILES

Users can do backups of file systems by: 

• keeping the duplicated files in external storage such as in the floppy disk and thumb drive 
• do backup frequently

2) DETECT VIRUS AND DO CLEANUP

A computer virus is able to affect and infect the way the computer works. Viruses can be detected when we run an antivirus program. We can also delete the infected files and documents.

3) WARN OTHERS ON VIRUS ATTACK

We can warn others on virus attacks or new viruses by sending e-mails to them.

DETECTING ILLEGAL ACCESS TO SYSTEMS

The computer system is able to detect any illegal access to the system by a user who does not have any authorisation. Basically, a corporation will simply use tcpwrappers and tripwire to detect any illegal access to their system. User's access will be reviewed periodically by computer operations. On going internal audits will be made to ensure detection of violations of security and unauthorised modifications to software and data.

TCPWRAPPERS

Tcpwrappers will control access at the application level, rather than at the socket level like iptables and ipchains. The system will run tcpwrappers to log access to ftp, tftp, rch, rlogin, rexec and telnet.

TRIPWIRE

Tripwire will detect and report on any changes in the thousands of strategic system files.

The system will run tripwire to determine if system files have changed.

PREVENTING ILLEGAL ACCESS TO SYSTEMS

Have any of you ever been to an airport? Do you know the do’s and don’ts when you are at the airport?

There are things that cannot be taken inside the airplane. It is for the purpose of security procedures.

It is the same as computer systems. It would not allow any unauthorised users to simply access the system.

Ways to prevent illegal access to systems:

1. Run anlpassword to make password cracking difficult.
2. Run tcpwrappers to check if the name for an ip address can be provided by DNC
3. Use a callback system to prevent unauthorised use of stolen passwords.

PREVENTING ILLEGAL ROOT ACCESS

To prevent any illegal root access, we should have Sudo, so that people can perform on some machine without getting access to the entire root if that is not required. In addition, with Sudo we did not have to give out the root password.

Sudo stands for (Superuser do) and  is a program in Unix, Linux and similar operating systems such as Mac OS X that allows users to run programs in the form of another user (normally in the form of the system's superuser).

Sudo allows a permitted user to execute a command as the superuser or another user, as specified in the sudoers file.

PATCH

Patch supplies small updates to software, provided that the source code is available.

Patch is a name of an UNIX utility. It applies a script

generated by the different program to a set of files

that allows changes from one file to be directly applied to another file.

Resources are not enough to patch all security holes that we hear about through the bugtraq list.

(Bugtraq is a full disclosure mailing list dedicated to the issues of computer security. On-topic discussions are new discussions about vulnerabilities, methods of exploitation and how to fix them. It is a high volume

mailing list and almost all new vulnerabilities are discussed there.)

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 Others Lesson : | click lesson to view |
 

• Define computer security. 
• Explain briefly the different threats to computer seurity
  
• Select the appropriate security measures to overcome the identified computer threat 
• Apply the correct security procedures.