Image-based completely automated public turing test to tell computers and humans apart (CAPTCHA)

摘要

An image is selected responsive to receiving an access request for access to protected content. An access code is assigned to the image, and the image is partitioned into a plurality of image tiles. Each image tile comprises a code segment, which is a part of the access code. The image tiles are then scrambled into a scrambled version of the image and displayed to a user. The user rearranges the scrambled version of the image to reassemble the image, identifies a correct sequence for the code segments, and then enters the code segments in the correct sequence as a codeword. The codeword is matched against the assigned access code. If they match, the user is granted access to the protected content. Otherwise the person is denied access to the protected content.