Method, apparatus, and computer program are disclosed for operating drones or other mobile computers in sensitive environments, where the drones are exposed to attacks with updates, incorrect/malicious commands or even being joined by malicious drones pretending to be part of the drone swarm or group. The method includes leveraging both trusted computing capabilities and that each individual drone can decide on the level of assurance and trust of any other drone we can construct a consensus algorithm such that if a drone wishes to perform a sensitive operation then all drones can attest that drone and decided on its level of assurance.