A high-level security policy states an overall requirement for a sensitive task. One example of a high-level security policy is a separation of duty policy, which requires a sensitive task to be performed by a team of at least <i>k</i> users. It states a high-level requirement about the task without the need to refer to individual steps in the task. While extremely important and widely used, separation of duty policies state only quantity requirements and do not capture qualification requirements on users involved in the task. In this paper, we introduce a novel algebra that enables the specification of high-level policies that combine qualification requirements with quantity requirements motivated by separation of duty considerations. A high-level policy associates a task with a term in the algebra and requires that all sets of users that perform the task satisfy the term. We give the syntax and semantics of the algebra and study algebraic properties of its operators. We also study several computational problems related to the algebra.