Security measures for signal paths with tree structures can be implemented at design phase using an EDA software program or tool with security feature functionality that, when executed by a computing system, directs the computing system to: display a canvas through which components of a circuit are arranged; and provide a menu of commands, including an option to add components from a library to the canvas and an option to secure a tree. In response to receiving a selection of the option to secure the tree, the system can be directed to add a hardware countermeasure coupled to at least two lines or terminal nodes of a tree structure identified from components on the canvas or in a netlist corresponding to a circuit's design.