New web security system tests computers' emotions

Sorting the men from the replicants.

A new Captcha system seeks to separate humans from computers by testing empathy – and spreading awareness of human rights human rights abuses at the same time.

A Captcha – which stands for Completely Automated Public Turing test to tell Computers and Humans Apart – is the test used when logging into many sites to distinguish between real people and malicious programs, which may attempt to log into many thousands of accounts at the same time. You've all used one – signing up for a New Statesman commenting account, if nowhere else – and they are ripe for being put to good use.

ReCAPTCHA was the first socially-beneficial captcha, and still the most popular. It uses the combined might of all the human brain power wasted on Captchas to transcribe scanned books:

reCAPTCHA improves the process of digitizing books by sending words that cannot be read by computers to the Web in the form of CAPTCHAs for humans to decipher. More specifically, each word that cannot be read correctly by OCR is placed on an image and used as a CAPTCHA. This is possible because most OCR programs alert you when a word cannot be read correctly.

Since it took off, ReCAPTCHA has been used on innumerable sites, and is now displayed over 100 million times a day. But that success comes at a price. Now that the low hanging fruit has been plucked, fewer and fewer easily-transcribable words remain in its corpus, meaning that the system regularly throws up completely unintelligible words, words in other scripts, or things which just aren't language at all.

The civil rights captcha wants to be the replacement. Rather than using the captcha to perform useful work, like reCAPTCHA, it uses it to raise awareness about important issues:

Instead of visually decoding an image of distorted letters, the user has to take a stand regarding facts about human rights. Depending on whether the described situation is positively or negatively charged, the CAPTHA generates three random words from a database. These words describe positive and negative emotions. The user selects the word that best matches how they feel about the situation, and writes the word in the CAPTCHA. Only one answer is correct, the answer showing compassion and empathy.

As well as being important socially – example questions include "The parliament in St. Petersburg recently passed a law that forbids "homosexual propaganda". How does that make you feel?" – the Civil Rights Captcha is stronger against attack as well. It includes the same visual element as a reCAPTCHA, requiring potential attackers to decipher obfuscated words, but also requires any automated attack to parse a complex question, pick the right emotion, and only then work out which of the proffered words match that emotion.

The whole thing is rather reminiscent of Blade Runner:

We'll catch those pesky replicants yet.

Rutger Hauer, in the film Blade Runner.

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

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Don’t shoot the messenger: are social media giants really “consciously failing” to tackle extremism?

MPs today accused social media companies of failing to combat terrorism, but just how accurate is this claim? 

Today’s home affairs committee report, which said that internet giants such as Twitter, Facebook, and YouTube are “consciously failing” to combat extremism, was criticised by terrorism experts almost immediately.

“Blaming Facebook, Google or Twitter for this phenomenon is quite simplistic, and I'd even say misleading,” Professor Peter Neumann, an expert on radicalisation from Kings College London, told the BBC.

“Social media companies are doing a lot more now than they used to - no doubt because of public pressure,” he went on. The report, however, labels the 14 million videos Google have removed in the last two years, and the 125,000 accounts Twitter has suspended in the last one, a “drop in the ocean”.

It didn’t take long for the sites involved to refute the claims, which follow a 12-month inquiry on radicalisation. A Facebook spokesperson said they deal “swiftly and robustly with reports of terrorism-related content”, whilst YouTube said they take their role in combating the spread of extremism “very seriously”. This time last week, Twitter announced that they’d suspended 235,000 accounts for promoting terrorism in the last six months, which is incidentally after the committee stopped counting in February.

When it comes to numbers, it’s difficult to determine what is and isn’t enough. There is no magical number of Terrorists On The Internet that experts can compare the number of deletions to. But it’s also important to judge the companies’ efforts within the realm of what is actually possible.

“The argument is that because Facebook and Twitter are very good at taking down copyright claims they should be better at tackling extremism,” says Jamie Bartlett, Director of the Centre for the Analysis of Social Media at Demos.

“But in those cases you are given a hashed file by the copyright holder and they say: ‘Find this file on your database and remove it please’. This is very different from extremism. You’re talking about complicated nuanced linguistic patterns each of which are usually unique, and are very hard for an algorithm to determine.”

Bartlett explains that a large team of people would have to work on building this algorithm by trawling through cases of extremist language, which, as Thangam Debonnaire learned this month, even humans can struggle to identify.  

“The problem is when you’re dealing with linguistic patterns even the best algorithms work at 70 per cent accuracy. You’d have so many false positives, and you’d end up needing to have another huge team of people that would be checking all of it. It’s such a much harder task than people think.”

Finding and deleting terrorist content is also only half of the battle. When it comes to videos and images, thousands of people could have downloaded them before they were deleted. During his research, Bartlett has also discovered that when one extremist account is deleted, another inevitably pops up in its place.

“Censorship is close to impossible,” he wrote in a Medium post in February. “I’ve been taking a look at how ISIL are using Twitter. I found one user name, @xcxcx162, who had no less than twenty-one versions of his name, all lined up and ready to use (@xcxcx1627; @xcxcx1628, @xcxcx1629, and so on).”

Beneath all this, there might be another, fundamental flaw in the report’s assumptions. Demos argue that there is no firm evidence that online material actually radicalises people, and that much of the material extremists view and share is often from mainstream news outlets.

But even if total censorship was possible, that doesn’t necessarily make it desirable. Bartlett argues that deleting extreme content would diminish our critical faculties, and that exposing people to it allows them to see for themselves that terrorists are “narcissistic, murderous, thuggish, irreligious brutes.” Complete censorship would also ruin social media for innocent people.

“All the big social media platforms operate on a very important principal, which is that they are not responsible for the content that is placed on their platforms,” he says. “It rests with the user because if they were legally responsible for everything that’s on their platform – and this is a legal ruling in the US – they would have to check every single thing before it was posted. Given that Facebook deals with billions of posts a day that would be the end of the entire social media infrastructure.

“That’s the kind of trade off we’d be talking about here. The benefits of those platforms are considerable and you’d be punishing a lot of innocent people.”

No one is denying that social media companies should do as much as they can to tackle terrorism. Bartlett thinks that platforms can do more to remove information under warrant or hand over data when the police require it, and making online policing 24/7 is an important development “because terrorists do not work 9 to 5”. At the end of the day, however, it’s important for the government to accept technological limitations.

“Censorship of the internet is only going to get harder and harder,” he says. “Our best hope is that people are critical and discerning and that is where I would like the effort to be.” 

Amelia Tait is a technology and digital culture writer at the New Statesman.