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  • Before you watch this video, to make sure you're not a robot,

  • please look at these pictures and identify the street signs, the cars,

  • the fire hydrants, the shop fronts,

  • the numbers on the front doors,

  • and the ever-growing sense of frustration.

  • In the late 90s the most popular search engine was AltaVista, and they had a spam problem.

  • People were writing automated scripts to send in spam and malicious links to their

  • finely crafted database of the web,

  • and they needed to add a test that only humans could pass.

  • Their solution was to add a question to the submission form that,

  • back then, only a human could answer.

  • In their case it was to identify a warped string of letters and numbers.

  • Image processing wasn't at the point where a computer could easily identify the squiggly letters,

  • but it was trivial for a human.

  • Or at least, trivial for a human with good eyesight.

  • Accessible versions didn't come along for a while.

  • But that was one of the first public versions of what became known as a CAPTCHA;

  • a Completely Automated Public Turing Test to Tell Computers and Humans Apart.

  • A version called reCAPTCHA came along a few years later:

  • it was used to help scan old books and newspapers.

  • When a CAPTCHA was needed,

  • the team would send one scanned word that they knew was right, deliberately distorted,

  • and another word that their scanning systems weren't sure about.

  • The user would have to type in both:

  • the known word was to check it was a human answering, they had to get that right,

  • but the unknown wordafter maybe a dozen people had agreed on what it was

  • that would be logged as part of the book scan.

  • Google ended up buying reCAPTCHA.

  • But by then, the arms race was well underway.

  • The bot makers looked at reCAPTCHA as a challenge,

  • and they rose to it admirably.

  • First, they could train computers to read those messed up words.

  • This was before the recent breakthroughs in machine learning and artificial intelligence,

  • but even a fairly rudimentary system could solve reCAPTCHA well enough to let bot-makers

  • create fake accounts and send spam some of the time.

  • If the test was still too difficult, though, they could just pay humans.

  • The bot makers set up systems where automated bots would fill in all the details,

  • ready to send spam, and then when the CAPTCHA appeared,

  • the bots would show it to human operators,

  • hired from countries where the average income is low.

  • Those humans got paid to sit there and solve CAPTCHA after CAPTCHA after CAPTCHA.

  • After all, it's only testing that there's a human in the loop somewhere.

  • You could even outsource your CAPTCHA solving needs to any one of dozens of companies

  • who all competed on price and accuracy.

  • Actually, you still can.

  • Or you could get unsuspecting members of the public to solve CAPTCHAs for you.

  • You could set up a web site with, er,

  • some images that some people might want to see(!)

  • and before they could visit,

  • they'd have to prove they were human by solving a CAPTCHA.

  • Which was copied straight from whatever site your bots were trying to get into.

  • So then Google released reCAPTCHA version 2.

  • Which is where you're presented with a single check box,

  • that you have to click on to prove you are not a robot.

  • And clearly, any bots presented with that box would be honest and not click it.

  • It's not really about clicking the box.

  • When you complete one of these new CAPTCHAs, extra data is sent.

  • And Google is very cagey about what that data is,

  • because everything they reveal is a clue for the people trying to break it.

  • But that box is loaded into your browser from google.com,

  • which means it can look at any login cookies that Google already have on your browser.

  • Certainly if you clear your cookies,

  • you are way more likely to get that secondary check

  • that asks you to identify buses or fire hydrants.

  • And maybe it checks how your mouse moves in the moments before clicking the box?

  • And the exact position and length of time your finger tapped the phone screen?

  • Plus a bunch of other things that Google all feeds into their giant machine-learning system.

  • The only people that know for sure are the designers, and they aren't telling.

  • The CAPTCHA solving services, of course,

  • are already offering a cost per thousand to solve these.

  • It may be harder, but it's not unbreakable.

  • Using machine learning,

  • bots can be trained to pass those secondary checks themselves, and to hide as humans,

  • well, identifying the correct sections of the presented images

  • is something that you can throw cloud machine learning at.

  • And given that Google Cloud sells machine learning systems,

  • it's very likely that some of their servers are creating CAPTCHAs,

  • and others are trying to break them. And, even then,

  • you can just have humans on standby instead.

  • So at the end of 2018, Google released reCAPTCHA version 3.

  • And you might have already passed, or failed, one of those without knowing it.

  • There's no box to tick, no puzzles to solve: when you browse round a site,

  • version 3 works in the background and watches what you do.

  • By the time you're posting a comment or signing up,

  • it's already assigned you a score based on how likely you are to be human.

  • And again, Google is being very careful about saying how they're working that out.

  • But the answer is very likelyit's a machine learning system they're throwing everything into

  • "and they don't know it works either”.

  • Hopefully they're taking account of incognito mode, and accessibility tools.

  • Because if you get a low score,

  • maybe your comment will get sent to a moderator to checkor maybe it'll just

  • disappear into nothing and you'll never know.

  • The bot makers, of course, are already working on the challenge.

  • I signed up for a new bank account online a few months ago,

  • and I had to send in a photo of my ID and a video of me holding that ID and waving.

  • That's checking not just that I'm a human,

  • but that I'm the one specific human I claim to be.

  • Bots are becoming more and more indistinguishable from humans.

  • Successful CAPTCHA methods are having to be more and more intrusive.

  • The arms race continues,

  • as it has done for twenty years or more.

  • I'm going to do something very strange for a sponsorship segment now:

  • I'm going to tell you about limits.

  • I've saidyou should use a password manager”.

  • And it's true.

  • I use one, I recommend you do too.

  • Which is why this video is sponsored by Dashlane, the password manager,

  • if you go to dashlane.com/tomscott,

  • you can get a free 30-day trial of Dashlane Premium,

  • and I recommend you try it out for yourself.

  • But there are some things that a password manager cannot help with.

  • If you are worried that a major government is trying to steal your secrets,

  • or industrial spies with millions of dollars of funding are targeting you specifically:

  • well, you probably already have professional advice.

  • After all, if someone actually gets to your computer's hardware and installs stuff

  • that pulls things right out of the physical memory

  • well, at some point,

  • even a password manager has to decrypt the password, put it in memory,

  • and pass it on to wherever you're actually trying to log in to.

  • If an attacker has physical access to the hardware, it's over.

  • And of course, the weak link in almost every security system is human.

  • All the security in the world cannot protect you from someone threatening you with violence

  • unless you type in your password.

  • And in the UK,

  • if the police have a court order requiring you to give them your password,

  • it is a criminal offence to refuse.

  • People have been jailed for it.

  • Dashlane cannot help you with that.

  • But using Dashlane means that every password is different,

  • so when some online service that you signed up to years ago and forgot about gets breached,

  • it's no big deal.

  • Actually, Dashlane will also warn you about data breaches

  • with instant alerts for websites where you have accounts.

  • Using Dashlane also means that every password is long, complicated and secure --

  • but you don't have to try and type them in on your phone,

  • because Dashlane will autofill them for you everywhere you go.

  • It can even auto-change passwords for you on a lot of sites, with the click of a button.

  • In short,

  • using something like Dashlane means that passwords stop being this worrying pain in the ass and

  • start being something that it's really easy to deal with.

  • I thought long and hard before accepting sponsorship for this series, but honestly:

  • if you are techie enough to watch these videos,

  • you should use a password manager.

  • So: dashlane.com/tomscott for a free 30-day trial of Dashlane Premium, and if you like it,

  • you can use the codetomscottfor 10% off at purchase.

Before you watch this video, to make sure you're not a robot,

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I'm Not A Robot ✅ ✅ ←これは (I'm Not A Robot ✅)

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    林宜悉 に公開 2021 年 01 月 14 日
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