Abstract: There are disclosed techniques for use in authentication. The techniques including setting a proximity threshold that represents a distance by which a first device and a second device can be separated without impacting authentication such that the selection is dependent on one or more environmental factors associated with the first device. The techniques also perform a comparison between the proximity threshold and a distance between the first and the second devices to produce a comparison result indicating whether the first device is proximate to the second device. Finally, based on the comparison result, the techniques determine whether to grant authentication such that at least one factor in the determination is the proximity of the first and the second devices.