Provided is a device for generating an identification key using a process variation during a manufacturing process of a conductive layer. The device for generating an identification key may include a conductive layer, which is disposed between a first node and a second node in a semiconductor chip, and which has a width that is at least a first threshold value but not more than a second threshold value, the first threshold value and the second threshold value being less than the minimum width according to the design rules that can ensure that the conductive layer is patterned such that the first node and the second node are electrically short-circuited, and a reader which provides an identification key by identifying if there is a short circuit between the first node and the second node.