A method for cryptographic data processing by means of a circuit comprises using a first circuit section to perform a first cryptographic operation in order to obtain first cryptographic data. The method further includes transmitting the first cryptographic data to a second circuit section via a transmission area of the circuit that physically separates the second circuit section from the first circuit section and whose resistance to attacks is at most as high as the resistance of the first circuit section. The method includes using the second circuit section to perform a second cryptographic operation using the first cryptographic data in order to obtain second cryptographic data.