300 results about "CAPTCHA" patented technology

In a system and method for the generation of attack-resistant, user-friendly, image-based CAPTCHAs (Completely Automated Public test to Tell Computers and Humans Apart), controlled distortions are applied to randomly chosen images and presented to a user for annotation from a given list of words. An image is presented that contains multiple connected but independent images with the borders between them distorted or otherwise visually obfuscated in a way that a computer cannot distinguish the borders and a user selects near the center of one of the images. The distortions are performed in a way that satisfies the incongruous requirements of low perceptual degradation and high resistance to attack by content-based image retrieval systems. Word choices are carefully generated to avoid ambiguity as well as to avoid attacks based on the choices themselves.

Methods and systems are described for generating captchas and enlarging a core of available captchas that are hard for an automated or robotic user to crack.

Techniques for granting access to an application or service based on a detected human stimulus at a computing device include detecting a stimulus that is generated by an external entity and independent of a CAPTCHA or CAPTCHA-like challenge. If the stimulus is included in a set of human stimuli, access to the application or service may be granted. Otherwise, access may be denied. The detected stimulus may be ad-hoc, or may be a response to an explicit challenge other than a CAPTCHA or CAPTCHA-like challenge. A background application may continuously test over time for ad-hoc stimuli that are consistent with a human presence, and may maintain or deny access accordingly. The detected stimulus may include changes in states of components of the computing device that are related to spatial orientation and / or location. Access to the application or service may be granted / denied based on the detected stimulus and an additional criteria.

The present disclosure involves a method. The method includes receiving a request from a user. The method includes constructing, by a computer processor, a media object that contains a plurality of media components. The method includes transmitting the media object to the user. The method includes prompting the user to perform a task involving at least a subset of the media components, the task including at least one of the following: selecting each of the media components in the subset according to a predefined sequence; and modifying at least one of the media components in the subset with respect to at least one of its following properties: location, size, appearance, and orientation. The method includes obtaining a description of an action performed by the user in response to the prompting. The method includes deciding whether or not to grant the request based on the obtaining.