Real-time techniques for determining all access requests to an attribute-based access control policy which evaluate to a given decision, “permit” or “deny”. The policy is enforced to control access to one or more resources in a computer network. In one embodiment, a method includes: (i) receiving a reverse query and a set of admissible access requests, each of which includes one or more attributes in the policy and values of these; (ii) extracting attributes to which all access requests in the set assign identical values; (iii) reducing the ABAC policy by substituting values for the extracted attributes; (iv) caching the policy as a simplified policy; (v) translating the simplified policy and the given decision into a satisfiable logic proposition; (vi) deriving all solutions satisfying the proposition; and (vi) extracting, based on the solutions, all access requests from the set for which the policy yields the given decision.