A group management server in a group information management system includes: a group member terminal list storage unit for storing a group member terminal list; and a secure communication unit for establishing a secure communication channel with a plurality of terminal apparatuses and communicating with each of the terminal apparatuses via the communication channel. Each terminal apparatus includes a tamper-resistant module. The tamper-resistant module includes: a group information storage unit for storing group information securely; a deletion unit for securely executing deletion, which is processing that affects the group member terminal list, of the group information stored in the group information storage unit; and a secure communication unit for establishing a secure communication channel with the secure communication unit and transmitting a complete deletion notification message via the communication channel.