There is provided a method (100) of authenticating a first device (120) to a second device (110) based on a number of data elements and based on a predefined recombination function known by the first device and the second device. The method is executable by the first device and comprises receiving (101) an input signal by the first device from the second device, the input signal being indicative of selected ones of the data elements, generating (102), by the first device, an authentication signal by using the recombination function and based on the selected data elements as input elements, wherein the authentication signal represents a basis for the second device for authenticating the first device, and sending (103) the authentication signal to the second device.