Changes
<math> sid, (U_1,y_1,...,U_{joiner},y_{joiner},...), kc_{i}, z_{i}</math>
==Session picking protocol for current occupant of the current session==
If <math>m</math> users are joining that session concurrently, there are <math>S_1,...,S_m</math> sessions in-limbo which are receiving shares and authentication messages.
The user <math>U_i</math> sends the shares and authentication token necessary for each session. The first session which receives all confirmations will become the main session, and the joiner user of that session becomes the current session. '''All other <math>S_j</math> results result in new session sessions <math>S_{j''}</math> to which <math>U_{joiner}</math> is added. previous "Previous active (current" ) session of the room becomes in-limbo.'''
in-limbo -> {in-limbo, dead, current}
current -> in-limbo