In this paper, we propose an architecture to integrate authentication and authorization schemes for constructing a secure Grid system. In our proposed method, SAML (Security Assertion Markup Language) and XACML (eXtensible Access Control Markup Language) play key solution roles in integrating single sign-on and authorization. IBM and Microsoft are already leading in the standardization of security for Grid computing. Nevertheless, we recommended SAML as an alternative to the existing standard that they recommend. Therefore, our proposed architecture opens up the possibility of adopting a variety of single sign-on technologies in constructing secure Grid computing. Additionally, in order to implement access control, we recommended XACML, which gives Grid computing an efficient way to implement role-based access control.