240 is initialized in such a manner that the computer platform 210 and the external verifier 245 share a secret such as an initialization seed 242 i e token the shared secret is coded into a one way function together with a reliable event such as a time value which is reliably known to both the computer platform 210 and the external verifier 245 at any time when the executed protected code 222 is in execution the computer platform 210 may be requested by the external verifier 245 to generate a liveliness indicator 243 according to the liveliness protocol to detect whether the executed protected code 222 is in a liveliness synchronization with the mutually known reliable event i e the executed protected code 222 has not been stopped or altered a comparator unit 250 of the external verifier 245 receives the launch time metric 232 and receives the run time metric 237 from the computer platform 210 in response to sending a request for the run time metric 252 to the computer platform 210 the comparator unit 250 also compares the launch time metric 232 and the run time metric 237 and determines whether the launch time metric 232 and the run time metric 237 match a verification unit 255 of the external verifier 245 may send a request for.