System and method for supporting scalable bitmap based P_Key table in a high performance computing environment. A method can provide, at least one subnet comprising one or more switches, a plurality of host channel adapters, and a plurality of end nodes. The method can associate the plurality of end nodes with at least one of a plurality of partitions, wherein each of the plurality of partitions are associated with a P_Key value. The method can associate each of the one or more switches with a bitmap based P_Key table of a plurality of bitmap based P_Key tables. The method can associate each of the host channel adapters with a bitmap based P_Key table of the plurality of bitmap based P_Key tables.