If you can’t tell the difference between an inkblot that looks more like “body builder lady with mustache and goofy in the center” than “large steroid insect with big eyes,” then you can’t crack passwords protected via a new scheme created by computer scientists that they’ve dubbed GOTCHA.
GOTCHA, a snappy acronym for the decidedly less snappy Generating panOptic Turing Tests to Tell Computers and Humans Apart, is aimed at stymying hackers from using computers to figure out passwords, which are all too often easy to guess. GOTCHA, like its ubiquitous cousin CAPTCHA, relies on visual cues that typically only a human can appreciate.
The password system, from the minds of three computer scientists at Carnegie Mellon University (including one who was involved in creating CAPTCHA), is described in a paper published last month and was discussed earlier this week at the Association for Computing Machinery’s Workshop on Artificial Intelligence and Security in Berlin, Germany. Their research was funded by the National Science Foundation and Air Force Office of Scientific Research.
The inkblot-enhanced system is designed to prevent hackers from using passwords stolen from websites or other sources to gain illegal entry to computers at banks, hospitals and other such outfits. Even though typical passwords are stored as complex cryptographic hash functions, robust computers can decode them. But with GOTCHA, those using passwords need to be able to solve visual puzzles simultaneously.
According to CMU, “To create a GOTCHA, a user chooses a password and a computer, then generates several random, multi-colored inkblots. The user describes each inkblot with a text phrase. These phrases are then stored in a random order along with the password. When the user returns to the site and signs in with the password, the inkblots are displayed again along with the list of descriptive phrases; the user then matches each phrase with the appropriate inkblot.”
While it might be near impossible for the average person to remember phrases describing inkblots, such as “red eyed cow running toward me,” the researchers believe that most people could match up phrases with inkblots if they get to choose from those on a list.
The researchers don’t think that computers can solve the puzzles though and have issued a challenge to fellow security researchers to use artificial intelligence to try to do so. You can find the GOTCHA Challenge here.
While GOTCHA is still going through the testing phase, here’s a collection of readily available password protectors for enterprises.