*: If private transmissions are not available, the system could instead transmit a cryptographic hash of the concatenation of the token and the sender's Telepathy identifier, which can easily be verified by the server, but cannot be reused. | *: If private transmissions are not available, the system could instead transmit a cryptographic hash of the concatenation of the token and the sender's Telepathy identifier, which can easily be verified by the server, but cannot be reused. |