Access in a knowledge graph, comprising nodes and edges connecting two or more nodes, is controlled by assigning each node to a non-intersecting zone. A first and second zone identifier, each indicative of a zone occupied by a node where an edge ends, are each stored. Determining an access graph comprising an access node for each zone, access edges representing edges between the zones, and a first list of the zones. Each entry in the first list relates to a zone and a second list of node identifiers, each indicative of a node occupying the zone. A first and second access control list, each related to a zone where an access edge ends and to which a access node in the access graph relates, are stored in each access edge.