(Press-News.org) Contact information: Byron Spice
bspice@cs.cmu.edu
412-268-9068
Carnegie Mellon University
Carnegie Mellon researchers use inkblots to improve security of online passwords
GOTCHA scheme could foil growing problem of automated brute force attacks
PITTSBURGH—Carnegie Mellon University computer scientists have developed a new password system that incorporates inkblots to provide an extra measure of protection when, as so often occurs, lists of passwords get stolen from websites.
This new type of password, dubbed a GOTCHA (Generating panOptic Turing Tests to Tell Computers and Humans Apart), would be suitable for protecting high-value accounts, such as bank accounts, medical records and other sensitive information.
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.
"These are puzzles that are easy for a human to solve, but hard for a computer to solve, even if it has the random bits used to generate the puzzle," said Jeremiah Blocki, a Ph.D. student in computer science who developed GOTCHAs along with Manuel Blum, professor of computer science, and Anupam Datta, associate professor of computer science and electrical and computer engineering.
These puzzles would prove significant when security breaches of websites result in the loss of millions of user passwords — a common occurrence that has plagued such companies as LinkedIn, Sony and Gawker. These passwords are stored as cryptographic hash functions, in which passwords of any length are converted into strings of bits of uniform length. A thief can't readily decipher these hashes, but can mount what's called an automated offline dictionary attack. Computers today can evaluate as many as 250 million possible hash values every second, Blocki noted.
Given the continued popularity of easy passwords, such as "123456" or "password," it's not always difficult to crack these hashes. But even hard passwords are vulnerable to the latest brute force methods, Blocki said.
In the case of a GOTCHA, however, a computer program alone wouldn't be enough to break into an account.
"To crack the user's password offline, the adversary must simultaneously guess the user's password and the answer to the corresponding puzzle," Datta said. "A computer can't do that alone. And if the computer must constantly interact with a human to solve the puzzle, it no longer can bring its brute force to bear to crack hashes."
The researchers described GOTCHAs at the Association for Computing Machinery's Workshop on Artificial Intelligence and Security in Berlin, Germany, Nov. 4.
Because the user's descriptive phrases for inkblots are stored, users don't have to memorize their descriptions, but have to be able to pick them out from a list. To see if people could do this reliably, the researchers performed a user study with 70 people hired through Mechanical Turk. First, each user was asked to describe 10 inkblots with creative titles, such as "evil clown" or "lady with poofy dress." Ten days later, they were asked to match those titles with the inkblots. Of the 58 participants who participated in the second round of testing, one-third correctly matched all of the inkblots and more than two-thirds got half right.
Blocki said the design of the user study, including financial incentives that were too low, might account for the less-than-stellar performance. But he said there also are ways to make descriptions more memorable. One way would be to use more elaborate stories, such as "a happy guy on the ground protecting himself from ticklers."
The researchers also have invited fellow security researchers to apply artificial intelligence techniques to try to attack the GOTCHA password scheme. Their GOTCHA Challenge is online at http://www.cs.cmu.edu/~jblocki/GOTCHA-Challenge.html
GOTCHAs sound much like CAPTCHAs, the scrambled-letter puzzles that Blum and his CMU colleagues created to protect websites from rogue automated programs. Like GOTCHAs, the widely used CAPTCHAs rely on people having visual skills that are superior to those of computers. But the researchers emphasized that GOTCHAs don't do the same task and are not an alternative to CAPTCHAs.
This research was supported by the National Science Foundation and the Air Force Office of Scientific Research.
Follow the School of Computer Science on Twitter @SCSatCMU.
INFORMATION:
About Carnegie Mellon University: Carnegie Mellon is a private, internationally ranked research university with programs in areas ranging from science, technology and business, to public policy, the humanities and the arts. More than 12,000 students in the university's seven schools and colleges benefit from a small student-to-faculty ratio and an education characterized by its focus on creating and implementing solutions for real problems, interdisciplinary collaboration and innovation. A global university, Carnegie Mellon has campuses in Pittsburgh, Pa., California's Silicon Valley and Qatar, and programs in Africa, Asia, Australia, Europe and Mexico.
Carnegie Mellon researchers use inkblots to improve security of online passwords
GOTCHA scheme could foil growing problem of automated brute force attacks
2013-11-07
ELSE PRESS RELEASES FROM THIS DATE:
Researchers regrow hair, cartilage, bone, soft tissues
2013-11-07
Researchers regrow hair, cartilage, bone, soft tissues
Enhancing cell metabolism was an unexpected key to tissue repair
Young animals are known to repair their tissues effortlessly, but can this capacity be recaptured in adults? A new study from researchers ...
Calcium and vitamin D improve bone density in patients taking antiepileptic drugs
2013-11-07
Calcium and vitamin D improve bone density in patients taking antiepileptic drugs
A recent prospective, randomized, placebo-controlled clinical trial reports that calcium and vitamin D supplementation improves bone density in a group of male veterans with epilepsy who were treated ...
Obesity may limit overall function 2 years after shoulder replacement surgery
2013-11-07
Obesity may limit overall function 2 years after shoulder replacement surgery
Obesity does not significantly impact short-term complications, outcomes
Rosemont, Ill. –Patients with obesity undergo a disproportionately higher number of elective ...
Blocking the active site of thiolase
2013-11-07
Blocking the active site of thiolase
This news release is available in German.
Scientists at the University of Oulu, Finland, and at the Helmholtz Center Berlin (HZB) have shown the way to new directions ...
Online course improves physicians skill level for detecting skin cancer
2013-11-07
Online course improves physicians skill level for detecting skin cancer
DETROIT – Primary care physicians who took an online training course about skin cancer detection significantly improved their skill to properly diagnose and manage benign and malignant ...
Vitamin C could ease muscle fatigue in chronic obstructive pulmonary disease patients
2013-11-07
Vitamin C could ease muscle fatigue in chronic obstructive pulmonary disease patients
Bethesda, Md. (Nov. 7, 2013)—Chronic obstructive pulmonary disease—a health problem in which the lungs lose their inherent springiness, making it progressively harder to breathe—can ...
1 worm, 2 mouths
2013-11-07
1 worm, 2 mouths
A devious evolutionary path between genetics and environment
Depending on the environment in which the worm grows, the larva of the roundworm Pristionchus pacificus develops into either a wide-mouthed predator or a narrow-mouthed bacteria ...
Crown of Venezuelan paramos: A new species from the daisy family, Coespeletia palustris
2013-11-07
Crown of Venezuelan paramos: A new species from the daisy family, Coespeletia palustris
A joint research led by the Smithsonian Institution (US), Saint Louis University (US) and Universidad de Los Andes (Venezuela) resulted in the discovery of an exciting new species from ...
For obese teen girls, aerobic exercise may trump resistance training in health benefits
2013-11-07
For obese teen girls, aerobic exercise may trump resistance training in health benefits
Bethesda, Md. (Nov. 7, 2013)—Obesity has more than doubled in children and tripled in adolescents in the United States in the past 30 years, according to the Centers for Disease Control ...
When is a comet not a comet?
2013-11-07
When is a comet not a comet?
Hubble astronomers observe bizarre 6-tailed asteroid
Astronomers using the NASA/ESA Hubble Space Telescope have observed a unique and baffling object in the asteroid belt that looks like a rotating lawn sprinkler or badminton ...
LAST 30 PRESS RELEASES:
Study tracks chromium chemistry in irradiated molten salts
Scientists: the beautiful game is a silver bullet for global health
Being physically active, even just a couple of days a week, may be key to better health
High-fat diet promote breast cancer metastasis in animal models
A router for photons
Nurses and AI collaborate to save lives, reduce hospital stays
Multi-resistance in bacteria predicted by AI model
Tinker Tots: A citizen science project to explore ethical dilemmas in embryo selection
Sensing sickness
Cost to build multifamily housing in California more than twice as high as in Texas
Program takes aim at drinking, unsafe sex, and sexual assault on college campuses
Inability to pay for healthcare reaches record high in U.S.
Science ‘storytelling’ urgently needed amid climate and biodiversity crisis
KAIST Develops Retinal Therapy to Restore Lost Vision
Adipocyte-hepatocyte signaling mechanism uncovered in endoplasmic reticulum stress response
Mammals were adapting from life in the trees to living on the ground before dinosaur-killing asteroid
Low LDL cholesterol levels linked to reduced risk of dementia
Thickening of the eye’s retina associated with greater risk and severity of postoperative delirium in older patients
Almost one in ten people surveyed report having been harmed by the NHS in the last three years
Enhancing light control with complex frequency excitations
New research finds novel drug target for acute myeloid leukemia, bringing hope for cancer patients
New insight into factors associated with a common disease among dogs and humans
Illuminating single atoms for sustainable propylene production
New study finds Rocky Mountain snow contamination
Study examines lactation in critically ill patients
UVA Engineering Dean Jennifer West earns AIMBE’s 2025 Pierre Galletti Award
Doubling down on metasurfaces
New Cedars-Sinai study shows how specialized diet can improve gut disorders
Making moves and hitting the breaks: Owl journeys surprise researchers in western Montana
PKU Scientists simulate the origin and evolution of the North Atlantic Oscillation
[Press-News.org] Carnegie Mellon researchers use inkblots to improve security of online passwordsGOTCHA scheme could foil growing problem of automated brute force attacks