The disclosure provides systems and methods for identifying a mobile device when requesting a secure transaction. In a method conducted at a transaction server access to stored location data having been periodically received relating to a mobile device and stored with an identifier of the mobile device is provided. Historical location data having been stored locally at a mobile device is received from the mobile device when requesting a secure transaction. The historical location data received from the mobile device is matched to a subset of the stored location data to obtain or verify an identifier of the mobile device requesting the secure transaction. The mobile device requesting the secure transaction is associated with the identifier so as to identify or verify the identity of the mobile device requesting the secure transaction.