A method for authenticating an online transaction or a log-in process is provided. The method comprises: receiving image data of a visual graphical barcode from a user device, and the visual graphical barcode is configured to be displayed on an unauthenticated device for conducting the online transaction; analyzing the image data to obtain a transaction validation identifier (ID); comparing the transaction validation ID to a pre-stored validation ID; comparing a first set of collection data from the user device to a second set of collection data that is pre-stored; and determining whether to approve or reject the online transaction based on (1) a match between the transaction validation ID and the pre-stored validation ID, and (2) a match between the first set of collection data and the second set of collection data that is pre-stored.
