An energy model for Internet of Things devices is proposed. The model is based on security mechanisms that are constantly used but never accounted for to allow for longer term conclusions on the energetic cost of security. It is suitable for networking scenarios by slicing the energy spent by a device in individual connections with other network elements. It presents a three phase view of a connection with external network elements: establishment, active communication phase and termination. It maps security mechanisms and offers the ability to quantify the costs of security algorithms in all the phases. It enhances the traditional models by introducing security as a basis and being suitable for networking considerations. Simulation results are presented that show better visibility of a device’s energy consumption while networking in cooperation scenarios and due to security options, using Bluetooth’s Low Energy most secure mode of operation.