A communication control device includes a receiving unit, a generating unit, and an output unit. The receiving unit receives input of a binary tree in which each leaf node has an index and a node key assigned thereto, and receives input of node IDs that, from among the leaf nodes, enable identification of the leaf nodes belonging to a group. The generating unit generates, using the node key assigned to the root node of each partial tree of the binary tree which includes only the leaf nodes identified by the node IDs, a cipher text by encrypting a group key shared in the group, and generates set information containing the generated cipher text. The output unit outputs the set information at least to the communication devices that are associated to the leaf nodes belonging to the group.