Computer Security

In general, a secure system will use some special secure features to control access of information. Only properly authorized people or the processes carry out in the name of these people can read, write, create, and delete information. With the development of computer hardware, the amount of programs and data are stored in the computer is become larger. How to protect the data in the computer from being lost, which should be the first consideration problem for any computer application department. Computer hardware and software production manufacturers are also trying to study and continue to solve this problem.

The main causes of losing data on a computer are: virus attack, theft, computer electromagnetic radiation, computer storage hardware damage and so on.
So far, there has found near million computer viruses. Vicious virus can crash the whole computer software system and destroy data completely. There are hundreds of such viruses. A computer virus is a small hidden program that attaches to computer software. It is similar with other working computer programs, but it will disrupt the normal function programs and data files. To prevent virus attacks, it mainly strengthen the administration, never open extraneous software, and text the system regularly. Also, we can insert the anti-virus card or use clear software to clear the virus that has been found on computers.
Thefts refers to people access computer systems in legal identity and extract data from a computer without permission to modify, transfer, copy and so on. One way to prevent is add software system security mechanisms so that thieves cannot enter the system with legal identity. For example, add recognition of legitimate users or password to stipulate different privileges for the users. So, it cannot freely access the data areas that should not be accessible. Second, encrypt the data. Even if the thieves get into the system,  they cannot read the data without the key. Keys can be soft code or hard code, but it requires being replaced at any time. Encrypted data has security in transmission. Third, setup operation log in computer. It automatically records reading, writing, or modifying important data. This log is a black box that only a handful of privileged people can open. It can be used to detect the theft.