A method includes receiving, at a computing device comprising a processor, a request to determine bicliques in a graph, where the graph includes a first set of nodes, a second set of nodes, and a set of edges, each edge in the set of edges connecting a node in the first set of nodes to a node in the second set of nodes. The method also includes determining at least one biclique based on querying a bitmap index representing the graph, where the bitmap index includes a plurality of bit strings corresponding to the first set of nodes, and where a value stored in a particular location in each bit string indicates whether an edge connects a first node corresponding to the bit string to a second node corresponding to the particular location.