Abstract. Trust can be used to measure our confidence that a secure system behaves as expected. We had previously proposed a vector model of trust [1]. In this work we address the problem of trust management using the vector model. We develop a new trust management engine which we call VTrust (from Vector Trust). The trust management engine stores and manages current as well as historical information about different parameters that define a trust relation between a truster and a trustee. We propose an SQL like language called TrustQL to interact with the trust management engine. TrustQL consists of a Trust Definition Language (TDL) that is used to define a trust relationship and a Trust Manipulation Language (TML) that is used to query and update information about trust relationships.