An anonymous reader writes CAPTCHA services that require users to recognize and type in static distorted characters may be a method of the past, according to studies published by researchers at the University of Alabama at Birmingham. Researchers focused on a broad form of gamelike CAPTCHAs, called dynamic cognitive game, or DCG, CAPTCHAs, which challenge the user to perform a gamelike cognitive task interacting with a series of dynamic images. For example, in a "ship parking" DCG challenge, the user is required to identify the boat from a set of moving objects and drag-and-drop it to the available "dock" location. The puzzle is easy for the human user to solve, but may be difficult for a computer program to figure out. The game-like nature may make the process more engaging for the user compared to conventional text-based CAPTCHAs.
There are a couple research papers available: "A Three-Way Investigation of a Game-CAPTCHA:
Automated Attacks, Relay Attacks and Usability
" and "Dynamic Cognitive Game CAPTCHA Usability and
Detection of Streaming-Based Farming