Does ROS use Open DDS (Real time publish subscribe (RTPS)) for communication? I have heard that it does. However, Open DDS does not yet support the Secure portion of the specification. If ROS does not use DDS, what is used for robot to robot communication or messaging? Such messaging or other communication strategies are important in robotic swarms. I am working on a contract with DARPA to implement Secure messaging done in a distributed manner such as is done with Blockchains. We are considering using Open DDS, but will need to find a way to add the Secure part of the specification. I would be interested to hear from anyone who has an overlapping interest in building support for such secure messaging.