A Software in the Loop (SiL) system and method is disclosed which may include a simulator operable to provide an environment to simulate dynamic systems, enable rapid development, validation of systems, and testing of complex systems. The system and method may include assembling one or more unsecured models operable to simulate the real-world system. The system and method may then encrypt and generate at least one secured model from the one or more unsecured models using a first cryptographic key. The at least one secured model may be decrypted using a sealed decryption key. The decrypted secured model may then be executed within the one or more TEEs. The at least one secured model may be operable to process incoming data and outgoing data.