Embodiments disclosed systems and methods to broadcast a message to one or more virtual data processing (DP) accelerators. In response to receiving a broadcast instruction from an application, the broadcast instruction designating one or more virtual DP accelerators of a plurality of virtual DP accelerators to receive a broadcast message, the system encrypts the broadcast message based on a broadcast session key for a broadcast communication session. The system determines one or more public keys of one or more security key pairs each associated with one of the designated virtual DP accelerators. The system encrypts the broadcast session key based on the determined one or more public keys. The system broadcasts the encrypted broadcast message, and the one or more encrypted broadcast session keys to adjacent virtual DP accelerators for propagation.