CAPTCHA technology under fire
CAPTCHA distorted-letter security test poses unacceptable difficulties for visually impaired users, says Australian Communications Consumer Action Network.PT1M58S http://www.canberratimes.com.au/action/externalEmbeddedPlayer?id=d-2raxe 620 349 August 6, 2013
It is one of the frustrations of the internet: trying to read those distorted letter puzzles that appear when signing up for an email account or web service.
Now, consumer groups are calling to abolish those blurry - and often illegible - words known as CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart), which are supposed to be easy for humans to read, but difficult for computers.
CAPTCHA tests stop spam by prompting consumers to prove they are human by retyping jumbled letters when signing up to new online accounts or posting online messages. They are also used to stop scalpers from scooping up thousands of concert tickets using automated software.
A mix of hard to read CAPTCHAs from the web.
But thousands of Australians who are blind or vision impaired are blocked from accessing websites that use CAPTCHA because they - or their screen reader software - cannot read the letters.
Teresa Corbin, chief executive of the Australian consumer group ACCAN, said that people with and without disabilities are increasingly frustrated by the use of these letters as online security tests.
“They fundamentally fail to properly recognise people with disability as human,” said Ms Corbin.
A CAPTCHA generated on Google's website for sign up.
ACCAN is joining with other groups such as Blind Citizens Australia, Able Australia and the Australian Deafblind Council to call on organisations to phase out their use.
A new "kill CAPTCHA" petition has been launched on change.org and has received dozens of signatures from people affected by accessibilty problems.
ACCAN disability policy advisor Wayne Hawkins, who is blind, said the letter tests disenfranchised large sections of the population and make it difficult for people with disability to access online government services.
Annoying: a campaign has started to kill off these fuzzy words.
"I have been blind for about seven years and CAPTCHA has fast become one of my most hated aspects of the web," Mr Hawkins said.
"I'm constantly frustrated when trying to book concert tickets online, contribute to online forums and email politicians through the contact forms on their websites."
He said audio CAPTCHA, which was supposed to solve the problem for blind or vision impaired people, is almost as inaccessible as the visual alternative.
But security experts say it is essential in preventing cyber criminals from creating thousands of rogue accounts on the internet.
"It is an inevitable safeguard," says AVG security advisor, Michael McKinnon.
"If we didn't have it we would be lowering the bar for criminals to be able to automate a lot of the work they do."
He said that some organisations have worked out how to subvert the safeguards, such as paying workers in low-cost labour countries pay people a few cents to answer CAPTCHAs for them.
"The reality is that even before we get to that stage there are so many websites that have no accessibility at all. Targeting CAPTCHA is unfair because disadvantaged users often can't even get that far."
The official web standards body, the World Wide Web Consortium, said there are many CAPTCHA alternatives, including simple maths questions, trivia, the use of sound files and even biometric technology such as fingerprints and retinal scanning. Microsoft have launched a substitute called Asirra (Animal Species Image Recognition for Restricting Access), that asks users to identify photos of cats and dogs instead of letters.
Asirra - which uses more than three million photos of cats and dogs - could be a simpler system as computers find it more difficult to recognise images rather than text.
"These alternatives show that there is no excuse for the continued use of this technology,” Ms Corbin said.
The Australian Disability Discrimination Commissioner, Graeme Innes, said he is unable to use text based CAPTCHA because screen readers can't recognise them.
"I can't use the audio ones because they are too hard to hear. There needs to be an alternative for people who are blind or have low vision."
Who uses CAPTCHA?
- Google (when signing up for an account)
- Microsoft (when signing up for an account)
- Shadow minister for disabilities Mitch Fifield (for contacting the minister)
- Deputy leader of the Opposition Julie Bishop (for contacting the minister)
- Shadow minister for education Christopher Pyne (for contacting the minister)