Privacy-enhanced SPKI access control on PKIX and its application to Web server

Access control using PKIX (Public Key Infrastructure with X.509) may cause a privacy problem. It is caused mainly by the fact that a server can know a client´s ID. To solve this problem, we proposed a restricted anonymous access control scheme using SPKI (Simple Public Key Infrastructure). It can make a server provide service to an authorized client. It still has another problem: SPKI is not so popular as PKIX. PKIX has many efficient technologies such like SSL (Secure Socket Layer), but SPKI can´t directly use these technologies. In this paper our implementation utilizes the slightest extension of PKIX, namely, we use an X.509 Certificate as an Authorization Certificate and PKIX technologies, i.e. SSL. Therefore, our approach can make some proposed SPKI schemes practical and useful. In this paper the proposed scheme is applied to access control of the Web server. The system demonstrates that it succeeds in adding privacy-enhanced access control to SSL mutual authentication. We also describe and discuss the details of implementations.