1. A method of determining whether a user of a mobile device corresponds to a previously authenticated user, the previously authenticated user having been previously authenticated using an identity document, the method comprising: accessing, by a chip reader associated with the mobile device, an integrated circuit component of an identity document; retrieving, by the chip reader from the integrated circuit component, digital image data indicative of a digital image of the previously authenticated user; capturing, using a camera associated with the mobile device, an image comprising image data, wherein the image corresponds to the user of the mobile device; comparing the retrieved digital image data to the image data; determining, based on the comparing of the retrieved digital image data to the image data, whether the captured image and the digital image represent the same user; and forming an association between the previously authenticated user and the mobile device when it is determined that the captured image and the digital image represent the same user.