Abstract: A system is provided for protecting a computer system and/or control system against manipulation and functional anomalies. The system includes a monitoring module, which has at least a first interface, a second interface, and at least one memory. The system is configured to receive information characterizing the system state of the computer system and/or control system via the first interface, receive an encrypted request for system state via the second interface and decrypt it using a request key stored in the memory, and generate a response to the request from at least a portion of the information received via the first interface. The system is also configured to encrypt the response with a response key determined using the request and output it via the second interface, determine a new request key which is a shared secret also accessible to the sender of the request, and store this new request key in the memory.