Cryptographic operation

A method is suggested for providing a response, wherein the method comprises: obtaining a challenge from a host, determining the response based on the challenge, determining an auxiliary value based on the response or the challenge, providing the auxiliary value to the host, obtaining a random value from the host, checking the validity of the challenge based on the random value, and providing the response to the host only if the challenge is valid. Also, according methods running on the host and system are provided. Further, corresponding devices, hosts and systems are suggested.