Attacks exploiting micro-architectural vulnerabilities, such as Meltdown, Spectre, Rowhammer,etc., are on the rise. Modern day SoCs "System-on a Chips" embed increasingly complex design features, such as branchprediction, Out-of-Order execution, cache coherency protocols, integrated GPUs/FPGAs, new nonvolatile memories. The security aspect of these new architectures and technologies remains under-studied. This project aims at modeling the architectural problems with a virtual platform based on gem5. It will be used for penetration testing, evaluate the performance cost of countermeasures,anticipate new attacks and propose protections. These latter are validated on platforms based on ARMand RISC-V processors. The major impact of this project will be through the creation of a community around the virtual platform. The project will be carried out in collaboration with the SME Secure-IC,which will give industrial insights to the project.