Design And Implementation Of A Security Enhancement Scheme For Linux Login Authentication

Information security is more and more important with the rapid development of Internet. As the first line of defence system security, the importance of login authentication of operating system is self-evident. On one hand, since operating system is not secure, a malicious user can take advantage of the vulnerabilities to intercept the user’s password. On the other hand, system users may have been using the same password for a long time in order to make the password easy to remember, or even the same password used for different purposes. Therefore, the security threat still exists even if the malicious programs are cleared off the system. It may bring huge loss to the user if password is lost.For specific security threat, this thesis improves the original system login authentication scheme under Linux environment. In this thesis, the password-input process is separated from the original login authentication system by using the pluggable authentication module (PAM) mechanism and Diffie-Hellman key exchange (DH) protocol. In order to protect the password input process, the password is encrypted and encapsulated using a special chip.The main works of this thesis are as follows:(1) A security enhancement scheme for Linux login authentication is proposed, which includes secure input module, the login authentication module and the password-update module.(2) The interface and function of these three modules are given here. Besides, interaction of these three modules are also described in this thesis.(3) These three modules are implemented in this thesis and the prototype system is given and tested here on domestic computer platform.