Methods of Defense

Methods of Defense:

We can deal with harm that occurs when a threat is realized against a vulnerability in several ways:

• Prevent it, by blocking the attack or closing the vulnerability.

• Deter it, by making the attack harder, but not impossible.

• Deflect it, by making another target more attractive.

• Detect it, either as it happens or some time after the fact.

• Recover from its effects.

Controls:

• Encryption

• Software Controls - access limitations in a data base, in operating system protect each user from other users

• Hardware Controls –smartcard

• Policies - frequent changes of passwords

• Physical Controls

Software Controls:

• Program controls include:

• Internal program controls: part of the program that enforce security restrictions, such as access limitations in a database management program.

• Operating system and network system controls: limitations enforced by the operating system or network to protect each user from all other users.

• Independent control programs: application programs, such password checkers, intrusion detection utilities or virus scanners, that protect against certain types of vulnerabilities.

• Development controls: quality standards under which a program is designed, coded, tested and maintained, to prevent software faults from becoming exploitable vulnerabilities.

Hardware Controls:

• Numerous hardware devices have been created to assist in providing computer security. These devices include a variety of means, such as:

• Hardware or smart card implementations of encryption

• Locks or cables limiting access or deterring theft

• Devices to verify user’s identities

• Firewalls

• Intrusion detection systems

• Circuit boards that control access to storage media

Policies & Procedure Controls:

• Controls can also be in place based on agreed-upon procedures or policies among users, rather than enforcing security through hardware or software means.

• Training and administration follow immediately after establishment of policies, to reinforce the importance of security policy and to ensure their proper use.

Encryption Controls:

• Encryption is the formal name for scrambling data so that interpretation is meaningless without the intruder’s knowing how the scrambling was done.

• Encryption can virtually nullify the value of an interception and the possibility of effective modification or fabrication.

• It clearly addresses the need for confidentiality of data.

• It also can be used to ensure integrity.

• Encryption is the basis of protocols that enable us to provide security while accomplishing an important system or network task.

Effectiveness of Controls:

• Principle of effectiveness: Controls must be used and used properly to be effective.

• There are several aspects that can enhance the effectiveness of controls:

• Awareness of problem

• Likelihood of use

• Overlapping controls

• Periodic review