Changes
/* Finite State Table */
| JOIN_REQUESTED || || authenticate and send share || || || ||
|-
| RE_SHARED || init a stale session with new user || authenticate and store share || authenticate and store share || authenticate and store share || ||
|-
| GROUP_KEY_GENERATED || init a stale session with new user || || || || mark confirmed and may move session ||
|-
| IN_SESSION || init a session with new user || || || || || receive
