Data security is the component of IT security services designed to protect computer systems. This includes prevention, detection and correction of unauthorized use of computer systems. But security also means protecting computer systems against other risks, such as loss of data due to a hard drive crash.
Basic principles in data security include: Privacy: preventing unauthorized access to information. Integrity: prevention of unauthorized or accidental alteration of information. Availability: prevention of unauthorized withholding of information. Since the Internet is accessible to so many nowadays, computer security has become a problem for the consumer. Some problems can be solved relatively easily by ordinary home users. However, there are other more advanced targeted attacks, against which an antivirus software may not help much.
The problem of computer systems lacking adequate protection for certain applications can not be resolved by the end user. Most computer viruses, Trojan horses and worms exploit bugs that are already known. By installing security patches from the software vendor, the end user can protect themselves against known threats. Many applications today have the functionality for automatic updates that simplify this process.
Viruses and malware are major threats to end user computer security. They can steal valuable information such as credit card information and login information, destroy data, or force the user to take advantage of advertising (adware).
The computer system must be able to prevent the direct or indirect alteration of information, either through unauthorized users or accidental events. The protection against attacks is achieved by acting on several levels: first, at the physical – placing the server in places that are as safe as possible, which comes with monitoring and/or access control. The second level is normally the one that provides the logical authentication and authorization to an entity that represents the user in the system.
Risk analysis or evaluation of all possible threats in terms of probability of occurrence and its potential damage, typically precedes implementation of protection measures, thus allowing to estimate the relative risk. FreeBSD, Linux and Mac OS X operating systems experience fewer virus attacks, this can be attributed to effective security configurations.
Microsoft Windows however is hard hit by the implicit requirement to update antivirus software for security measures to be useful and thus get effective protection against known virus threats. Antivirus programs need regular updates of their virus definitions. Antivirus software can be quite taxing to system resources to the extent of slowing the machine down. It protects not only against computer viruses, but also against some other malware – but does not cover all threats.
Passwords should not be written down and kept near the computer. Passwords must therefore be fairly easy to remember and should be changed at least once every six months. Use of upper and lowercase letters and some numbers and special characters is encouraged. Passwords with 1-7 letters from A to Z, with uppercase or lowercase letters and numbers are now counted as unsafe, this is because an ordinary PC can try to crack them in less than a month. Nowadays, it is often possible to use a pass phrase in place of a password. A phrase consisting of normal words should then be much longer than a well-chosen password.