Using camera signatures from uploaded images to authenticate users of an online system

A computer-implemented method for authenticating a user of an online system, the method comprising:

• storing one or more camera signatures associated with the user, wherein each camera signature comprises characteristic information about the camera obtained from images taken from the camera;
• receiving a request for access to information from a user;
• sending a request to the user to upload an image;
• responsive to receiving an uploaded image, matching the uploaded image with a camera signature, wherein matching comprises comparing attributes of the uploaded image with the values of attributes associated with the camera signatures associated with the user;
• and
• responsive to the uploaded image matching at least one of the camera signatures associated with the user, granting access to the requested information to the user.

A computer-implemented system for authenticating users of an online system, the system comprising:

• a computer processor;
• and
• a computer-readable storage medium storing computer program modules configured to execute on the computer processor, the computer program modules comprising:
• a camera identification module configured to:
• receiving images from a user of an online system;
• analyzing the images to identify a plurality of images with matching information;
• associating the plurality of images with a signature of a camera;
• and
• associating the camera with an account for the user;
• and
• an authentication module configured to:
• receiving a request from the user for access to the online system;
• sending a request to the user to authenticate the user's account by providing one or more additional images taken from the camera;
• receiving the requested one or more additional images from the user;
• comparing the one or more additional images to the signature of the camera;
• and
• responsive to the one or more additional images matching the signature of the camera, providing the user with the requested access to the online system.