SECRET is a collaborative European Training Network (ETN) committed to create an "excellent" educational training platform for Early Stage Researchers (ESRs) in the field of wireless communications and networking for 5G. The project is recently funded by the European Commission under the H2020 research and innovation program, through the Marie Curie People Program.This proposal targets to narrow the gap between current networking technologies and the foreseen requirements of future 2020 networking, through the recruitment and training of 17 ESRs. SECRET aims to strike a note by delivering higher capacity, ability to support more users, and lowering the cost per bit by adopting technology trends widely accepted to form part of the 5G roadmap, through the deployment of new disruptive "femtocell" type cells on demand, to what we refer to as mobile small cells. This will be complemented by a wireless high-speed fronthaul to bridge the small cell network to the core. Moreover, novel techniques will be investigated, including "network coding", "cooperation", and "energy-aware smart front-end". Additionally, due to the confidential information that will be communicated over in future networks, a lightweight security framework built on secure network coding will be proposed.