ABSTRACT
With the rapid development of network technology, information security has been a great threat; the security of network information becomes particularly important. User login password verifies that user is legitimate or not, which is an important basis. How to ensure user login password security becomes the focus of user security. Once the user login information was leaked, intercept or tamper, it will bring enormous threat to users, the government and enterprises. Traditionally, the user login username and password are encrypted using a simple encryption technology directly in the network remote transmission, so it is easy to be intercepted and listened, and obtain the user’s important information. Database stores the user login user name and password, which is very easy for illegal personnel to be attacks on[1], user login information are large area leaked. Therefore, the MD5 algorithm is proposed to encrypt the user login password, it can protect accuracy and integrity of the user login information. However, with the progress of science and technology, MD5 algorithm has been cracked constantly. The MD5 algorithm has been cracked constantly, for the exhaustive attack and collision attack. A new MD5 algorithm improvement scheme is put forward. The improved MD5 algorithm changes and processes the user login password itself and messages through the MD5 algorithms encrypt. The user login password encryption adjustment effectively increase difficulty of the exhaustive attack, the changes of ciphertext can effectively prevent the collision attack.
