The VNF hopping in a Software Defined Network (SDN) allows a traffic flow to change routes frequently amongst a chosen group of paths to obfuscate data paths or to meet specific performance requirements while satisfying the service chaining requirements by activating in real-time the same virtual functions on each chosen path. Using the VNF hopping method and additional capabilities built into an SDN controller and an orchestrator according to this invention, the controller determines multiple feasible routes for specific flows with desired service chaining functions and enables activation of those chained services, so that the active flow can randomly be assigned to different routes after a switch-over time period expires, or by a special randomization logic within the switch managed by the controller, or manually programmed by a system administrator.