Changes
/* Send */
|-
|align="right"| Append the hash of the session digest up to parent of current message
|align="center"|<math> m \leftarrow (m, Digest(parnetparent(m)), parent\_id) </math>
|-
|align="right"| Sign the message
|-
|align="right"|Encrypt
|align="center"|<math>e \leftarrow Enc_k_Enc_{k_{sid}}(m)</math>
|-
|align="right"| Broadcast the message
