Trust management represents today a promising approach for supporting access control in open environments. While several approaches have been proposed for trust management and significant steps have been made in this direction, a major obstacle that still exists in the realization of the benefits of this paradigm is represented by the lack of adequate support in the DBMS. In this paper, we present a design that can be used to implement trust management within current relational DBMSs. We propose a trust model with a SQL syntax and illustrate the main issues arising in the implementation of the model in a relational DBMS. Specific attention is paid to the efficient verification of a delegation path for certificates. This effort permits a relatively inexpensive realization of the services of an advanced trust management model within current relational DBMSs. Categories and Subject Descriptors H.2.4 [Database Management]: Systems—Relational databases; H.2.7 [Database Management]:...