Broadband Dial-up Authentication Security Technologies And Applications Research

Recently Shanghai Telecom broadband business grows rapidly with the Internet development. Until 2007, broadband users had reached more than three million. The broadband business is mainly employing PPPoE and Radius protocols as the main dial-up authorization mechanism. These two protocols are mature and have been used in various fields. But at the same time they are facing some security issues, like the security issue of the dial-up software, the encryption issue of the dial up process, etc. These issues not only caused the financial lose of the customer and Shanghai Telecom company, but also affect the quality of the service. They are hindering broadband business from going further.The paper make a study of security vulnerabilities in current broadband dialer software by means of analyzing these two protocols and then propose a series of improvement schemes according to them. Firstly, we develop PPPoE dial-up client-side software, which can solve the copyright and security problem of software. And the software can be downloaded by broadband users. Secondly, we use irreversible one-way encryption to encrypt users' passwords in database, which can solve the security problem of users' information storage. Thirdly, we use symmetry encryption to encrypt password inputted by user on client-side and decrypt it on authentication server-side, which can solve the security problem of data transmission. The scheme covers the whole process of dial-up and takes client-side and server-side into consideration, which can effectively solve the security problem of broadband dial-up authentication. Up to now, we have developed PPPoE dial-up client-side software and accomplished encryption of users' passwords in database. Besides we have also made a feasible study of encryption on client-side, that is to recognize different clients by means of simply encrypting accounts. Although these are only a part of the total solution, the security of broadband service has been improved rapidly, and these research results have been confirmed by Shanghai Telecom and have been used practically.