By the technology development, the price of computer has become lower and lower. For this reason, a majority of family can afford this technology. A large amount of applications software were made for personal used computer. In addition, computer is not only a communication, entertainment and business tool; it also plays a role of information storage tool. For example, people will store their privacy information in personal computer, companies and organization will store their business record and employees information in computer. Moreover, the ministry of national defense will also store their country's confidentiality in computer. Therefore, computer's security is extremely important for every user.

On another aspect, a lot of hackers are appearing while computer is developing. Inventors also concentrate on security development after they realize this problem. From the early physical key protection, user name and password to biometric protection on nowadays, the protection of computer has catch up with the latest security problems. Obviously, security development is looking for a unique accessing path for every user. According to Reid (2004, p. 8), biometric computer security systems tie a unique physical attribute of a user to the IT resources and data that they are allowed to access. For this reason, biometric computer security systems basically achieve the purpose of security development.

As the literal meaning of the term biometric computer security systems, it is a special method for security system to recognize the unique parts of human. In this information age, a lot of biometric technologies have come out for security, such as fingerprint, hand geometry, retina, iris, face, signature and voice (Biometric Security Technology 2009). In addition, most of the technologies that mentioned above are commonly used on personal computer and human's daily life. This report will focus on these technology used on computer security problems and compare their benefits and drawbacks.