The Mighty River share float is now history. I followed the process with some interest. I was quite impressed with the steps Treasury had taken to make the share offer document accessible, including providing descriptions of some of the graphs and pie charts. Probably this was one rare occasion in which blind people interested in investment opportunities genuinely had equal access to the same information as sighted people.

The Mighty River share float is now history. I followed the process with some interest. I was quite impressed with the steps Treasury had taken to make the share offer document accessible, including providing descriptions of some of the graphs and pie charts. Probably this was one rare occasion in which blind people interested in investment opportunities genuinely had equal access to the same information as sighted people.

If you wanted to buy these shares, there were I think two ways to do it. One involved requesting that they post you a printed form which you could fill in and return. The other involved applying online.

If I had wanted to buy these shares, I would have preferred the online option. After all, to fill in a form means I have to ask a sighted person to do that for me. Blind people more and more these days are able to do a lot of things for ourselves with complete independence, because more and more things can be done online.

But blind people who wanting to buy these shares through the online process came face to face with a rude shock in the form of a visual CAPTCHA. This is a test where something is displayed in the form of distorted letters which you need to identify and decipher. You then enter these letters into the form. If you get it right, you can go on to the next step. If you get it wrong, you are blocked and you can’t go any further.

CAPTCHA is commonly used by websites to guard against abuse by computerised systems. Since only a human can supposedly pass the test, it means it is very hard for people to abuse the website with spam and other malicious software.

However, CAPTCHA, by its very nature, is discriminatory. Essentially it attempts to determine that the entity responding to a challenge is a human, but it can only really do this by looking for a certain attribute that only humans have, such as the ability to recognise visual images. A disability by its very nature robs a human being of certain attributes. If a particular CAPTCHA test relies on a human attribute, such as being able to see or hear, that the user does not have, the CAPTCHA test may well conclude that the user is not human. Imagine the anger you would feel if you are a genuine human being, but a given website basically says you are not.

In my view, any website that uses CAPTCHA in the context of delivering goods and/or services to the public risks breaching the Human Rights Act 1993, because it acts to prevent people with certain disabilities from accessing those goods or services. Then, under the Act, the obligation falls on the owner of the website to justify that it would be an unreasonable or undue burden to provide an alternative system for disabled people unable to pass the CAPTCHA test. But that assumes CAPTCHA is necessary in the first place. I accept that there is sometimes no alternative other than CAPTCHA in some situations. One example might be certain blog sites where comments are automatically published once they are submitted.

But I often find CAPTCHA is used in situations where it seems to me it is not really needed, and this is one of those situations. Think of all the bits of information in this case that would be checked before the transaction can actually go ahead. You would need your name and address, IRD number, a bank account number, and optionally your shareholder number. It would be relatively easy to validate such information, and that must happen anyway just to avoid mistakes. It would be extremely difficult for any automated malicious process to submit information that would pass all the tests, so I think it would be easy to quickly filter out any bogus information entered maliciously. And think of all the forms that came back through the post. Someone has to enter all that information into the database, so that must also be checked for validity and to guard against mistakes. And finally, let us not forget that this is a binding commitment, so if the Government is going to enforce its rights, it really needs to be sure this information is correct.

So CAPTCHA really doesn’t add anything in a case like this to the tests already available to check that each transaction is valid. Furthermore, there are a number of other techniques web developers can and do use successfully to guard against malicious submissions. I believe CAPTCHA is often used simply because it can be implemented in just a few lines of code – the developer can paste that in to the form and quickly go on to the next problem. I have already stated that CAPTCHA is discriminatory by its very nature. Anyone who uses it risks breaching the Human Rights Act, and may not have a defence if they can’t show it is justified.

I raised this with the Treasury people. They quickly replied to advise that the “accessible” version of the application form was now available. When I checked this out, I found it had a new type of CAPTCHA with an audio option. Most people seem to take the view that providing an audio option satisfies the requirement of accessibility. Actually it doesn’t for a number of reasons, not the least of which is that the person might be deafblind or just may have a hearing impairment that prevents them from hearing what is spoken.

Now have you ever actually listened to an audio CAPTCHA? There are some reasonably good ones, but of course the whole idea of CAPTCHA is to distort the audio otherwise it defeats the purpose because computers are getting pretty good these days at understanding speech. But I found this one to be pretty impossible. If CAPTCHA is just too distorted, then maybe that also defeats the purpose, if people genuinely can’t decipher it. I tried a couple of audio tests on this website but I couldn’t get it. I also downloaded a sample and sent it to the Treasury people. I was pleasantly surprised when they replied to say nobody in the office could figure it out either, and they would look more into this problem next time. Now we know it will be the turn of Meridian Energy to be sold later this year. We’ll wait to see what happens.

I should point out that I indicated to the Treasury people that I would not be buying any shares, so I can’t say the CAPTCHA test actually prevented me from completing my transaction. It would have been interesting to find out if they were in any position to give me a way forward had I been keen to buy them.

Blind Citizens NZ has now adopted a policy document on CAPTCHA that will be published later this year and will be available on this website. It explains in some detail the most significant problems inherent in CAPTCHA. It makes the point that people who deliver goods and/or services through websites that use CAPTCHA must stop and consider the human rights issues. We also make the point that website owners probably rely on their developers to give them good advice, but we suspect developers do not fully understand the human rights issues involved.

CAPTCHA works like a road-block. It’s like someone in a wheelchair is navigating their way through your building but then comes face to face with a staircase they can’t get up, and there is no way around it. First we challenge website owners to think carefully before using CAPTCHA because in many cases it won’t actually be needed at all. But then we say if you must use it, then you must also consider whether you can provide a clear alternative to someone who, for whatever reason, can’t pass the CAPTCHA test. A simple idea might be to still use the other techniques well-known to developers to filter out malicious submissions, then accept the submission but flag it for attention by someone in a call centre who can just phone the phone number and validate the submission over the phone in much the same way banks do. Under the Human Rights Act 1993, you are expected to take reasonable steps to accommodate the needs of people with disabilities. Putting in a road-block and doing nothing to help people with disabilities get around it is no longer acceptable.