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In this article:
- Meaning of Computer Security
- Techniques under Computer Security
Meaning of Computer Security
A computer many a times contains important information that needs to be protected from any unauthorized access. This information may be anything from a file storing data about employees to passwords. Computer security deals with controlling such and other risks that are involved with the use of a computer.
The aim of computer security and its techniques is to create a platform where the users of the computer (which maybe a human user or a program itself) can only access and modify those parts of the computer that they are authorized to. The scheme or set of rules that specify who is allowed to do what is called the security policy of a computer system. There are various limitations that can be enforced such as restriction of access or modification or deletion or a combination of these.
An important aspect of computer security is that it does not render a system useless; it only prevents its misuse by unauthorized users. Therefore, a computer system locked away from any power inside a box is not said to be useful though it is secure. In a secure system the authorised users of that system are still able to do what they should be able to do.
Computer security however has one important implication. This implication is highlighted when we talk of a computer which is not secure by virtue of its design itself. Techniques of computer security can not make a computer which is inherently insecure secure without compromising on its usablility. This means that to make such a computer secure, one or more of its features has to be limited in use or completely blocked, if need be.
Techniques under Computer Security
Computer security is broadly divided into two approaches to it. These two approaches are computer security itself, which considers a computer system insecure in itself and computer insecurity, which assumes a computer system to be a ‘trusted’ or ‘secure’ system.
Under the first approach, the aim is to redesign (not in hardware terms) the system in such a manner that it becomes more secure. Under the approach of computer insecurity, the main aim is to protect the system from external threats only. Depending on the situation and the environment, either of the two approaches maybe effective.
Some of the techniques used for securing a computer system are discussed below:
- Automated Theorem Proving
Automated theorem proving is actually a field of study under automated reasoning where mathematical theorems are proven by a computer program. By putting this into use for computer security, some critical algortihms are proven by the computer itself, telling if it is secure and if yes, to what degree. In this way, programs that do not contain any bugs. Examples include EROS and Coyotos microkernels.
- Cryptographic techniques
To make data being communicated over a network or other medium secure so as to prevent unauthorized access after it is intercepted, cryptogarphic techniques are used. This also involves the use of some very strong authentication tachniques so that end-points of a comunication are real (that is, the same that were meant to be commuinicating).
- Chain of trust
Under this technique, all hardware and software components of a system are validated as being authentic one after the another starting at the bottom-most level.
- Mandatory access control
This technique allows system administrators to specify a minumum level of restriction on use of resources. These restriction requirements are also applicable to the resources created by some other user of the system as well. So, such a user cannot provide a lesser degree of restriction to resources that they own.
- Backups and Other Protection
Data contained in a computer system needs to protected from loss due to an unplanned for event (contingencies) such as a system crash or accidental deletions. This involves use of backups whereby the data is saved on a storage media other than the usual ones used daily by the system. This includes CD-Rs, CD-RWs and DVDs etc. On the other hand, anti-virus software protect computer from being affected by malware including computer viruses. Firewall software prevent unauthorized of the computer over a network. Encryption techniques are used to encode data in a format not understandable normally.
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