Will Solve Captcha for Money?

alx_lo writes "Captchas are a nice idea to protect your blog or guestbook from being spammed by robots. But what good is this protection when you can hire "data entry specialists" to solve captchas for $0.60 per hour for 50 hours a week? Anyone here who can think up a solution that does not include drastically changing the global economy? How about captchas that require cultural background knowledge to solve?"

Comments

no good solution for now

[PrinceAshitaka]

The cultural background idea sounds good, but that may just reduce the number of Captchas these laborers can solve in an hour. A simple internet search should be able to solve these questions. What would be a few examples of a good Captcha for Americans. You will always find a good portion of Americans that are unable to answer even the simplest.

US customs has been known to ask cultural questions at border crossings. My sister was once asked what Dan Quayle's parents did for a living after she said she lived in Indiana. This question is a bit before her time. (His parents ran a newspaper in Indiana.) This also brings into question age. My parents kill me in the original version of trivial pursuit that they play, but I win when playing the newest version.

A temporary stop gap measure might be to use the current Captchas in combination of looking at the users geolocation. I can see how this measure though would really anger free speech advocates for the third world.

How about a mathematical Captcha that cannot be solved with a calculator. Well educated foreigners will not even work for $.60. Then again, how many Americans could solve these.

Re:no good solution for now

[mgblst]

Maybe we can have maths and physics questions - sure they will learn, but this is a good thing. We can underhandedly teach kids maths and physics around the world. This could be the problem to schooling.

Re:no good solution for now

[hc5duke]

Ok, I was being a smart-ass with the initial response, but I'm confused --

• If you ask something like "Sqrt(1048576)" most (all I hope) calculators will give you 1024, no approximation errors will/should be introduced anywhere.
• If you ask something like "Sqrt(2)" you would most likely have to settle for approximations, by hand or computer. (I think this was mentioned by 3-4 posters already, but just mentioning it anyway)
• I suppose there are cases with a definite answer, where computers will generate approximation errors, but my guess is that these would take too long for most (yes that includes non-Americans) people, and they'll just go to another site that offers your exact same service.

Basically what I'm saying is, give me an example of such a problem.

Re:no good solution for now

[jqh1]

One thing I've tried recently is to require some information that is contextually relevant, but not obvious from the information surrounding the challenge (which is not captcha, just a form input). For instance, on my blog, I'm requiring that a comment poster supply the name of the blog (which is in bold letters at the top of the page). For real posters, this is no doubt annoying, but the name of the blog is somewhere near the top of the stack in their brains. For a spammer, who's racing through a bunch of blogs to post comment spam, this likely is completely out-of-band. So far (about 3 months) it has completely stopped comment spam. Of course, I don't have info on how many real posters have clicked away from the page in frustration, but I have continued to get real comments at about the same rate as before.

If this sounds like a good idea, do something else, so that there's no pattern :)

"Who's Hot"

[neoform]

I remember seeing an example of a captcha type game a while back where you would have to pick the hottest girl out of 3 pictures in order to continue..

problem of course is when people disagree on what's "hot"..

refundable micropayments.

[yourestupidjerks]

Refundable micropayments. Seriously. Require people pay $1 to post a comment, payable via paypal or whatever. Once you have checked their comment, you can add them to a whitelist that will never be charged again and refund them their $1. Spammers don't get their dollar back, don't get added to the whitelist, and have their comment removed. The result over the course of a large number of blog entries would be to significantly increase the cost of doing business for spammers, while providing only a very minor inconvenience for legitimate users.

Reputation ID

[robotsrule]

This is why I believe in the future there will be two Internets. The one we have now which is wild and wooly where you can remain anonymous, and one where you can't do anything without a Reputation ID that is tied to a biometric identification method (fingerprint, voiceprint, etc.). There will be third party companies like Google that have Reputation ID accounts and will handle the authentication. The Reputation ID based Interent is where eCommerce, government and medical records, etc. based web sites will live.

I hope to heaven that instead of a biometric authentication, someone can come up with a card reader for driver's licenses or some other ID method, but current events seem to indicate biometric authentication will prevail. Even in that case, I hope it is a "authenticated-user" token passing scheme so that the web site that you want to visit never knows who you are, just that you are a valid user that owns the account ID you claim to own (the Reputation ID web site acts as middleman and privacy shield, pray they are never hacked).

By the way, I don't like the thought of privacy problems and Reputation ID spoofing scenarios this implies. I just don't see any other way way to build an Internet with a high degree of trust. As I type this I am looking at the SlashDot captcha box for comments.

Moderation

[truthsearch]

I helped develop one of the largest websites in Europe (in terms of traffic and volume of content). Human spammers have been bypassing our CAPTCHA for a while now. We still keep the CAPTCHA to block most bots. The data input goes through a custom spam filter. These human spammers are trying to spread their URLs, email addresses, and phone numbers just like most spam, so this helps to a large extent. Anything that gets through that can be flagged as spam by users. On top of all that there's some human moderation by the business which owns the site.

So in the end spam filters can help but human moderation is still the only real working solution today.

Solution using existing websites

[Facouille]

To register, you have to be a "confident" user of a parternship website, like say ebay, paypal, amazon, yahoo, hotmail, google, etc, etc. They can proof that you are a real user, and an open api allows 1-1 relations between your accounts. If you are not registered to any of those website, you have to get X points using Folding@Home to be trusted.

Use a human then.

[Xzzy]

Just have a human authorize every account creation. For smaller sites (the vast majority of the web) this might introduce a load of one authorization a month. As site size scales upwards, you have more people available to help with authorization. Could use the principles of the turing test to work through a 2 or 3 email exchange.

Could make the supporting cgi scripts as simple or as complicated as one's willing to author. One forum I maintained for a while had a low level "all access" section where new users posted an application. Forum regulars would respond, and eventually grade the new user. If they passed, they were given full access to the board. Granted, this system was employed more to limit the quantity of asshats than spammers, but the same principles apply.

It might even benefit society in the long run as a spammer's urge to do his work forces him to develop a "true" AI. ;)

Japanese cultural capchas

[kahei]

I've visited a Japanese art site (ie pictures of characters from fighting games drawn in alarmingly extreme detail) which had roughly this on the front page:

"Because there have been some people coming in here and stealing pictures or linking without permission, I have had to put this small test up. Please enter the Emperor's birth date in Japanese calendar in the box below. I'm sorry for this inconvenience and I will remove it when they forget about this site."

I've also seen a site (again in the 'students with too much time on their hands' sector) that asked for some other date in Japanese calendar. There are also a fair few personal sites that have a front page with just one link that takes you in, and several spurious links, with the page being 100% japanese text -- which I think serves about the same purpose.

On a related note, there also used to be WinMX groups which required that you say something in Japanese on entering or be booted. The point there was that otherwise you'd get masses of Korean 12-year-olds coming in and going 'Fuk Japanese bitch! dokdo nun uri tang!!lolz0rz!' and generally spamming the place. At least, I hope they were 12.

So, cultural captchas certainly exist... but it's easy to see why they work better on 'my pictures of Vampire Hunter D' sites than in the commercial world.

Re:Unique Reg Form

[soliptic]

I actually did something fairly similar with my phpbb installation.

I noticed that bots were signing up but not actually posting, (I donno, maybe they were meant to post but that part of the script broke -- either way, they never posted, but it annoyed me having them there.) They were just there, with links to sites selling vicodin/viagra/etc. Which annoyed me somewhat, but one time a child porn link showed up which was really the straw that broke the camels back, and I decided to stop it. I noticed that 99% of the sites were *.ru so I altered the reg form to throw an error if it detected a *.ru domain in the website field. Then I just started getting non *.ru domains instead, so I just thought, fine, fuck it.... Now if anybody signs up with ANY website in the website field, it throws an error, and has a message along these lines:

I notice you have a website listed. To prevent spam bots signing up to link their websites, this has been disabled on registration. If you are not a spam bot, just complete your sign up with no website, you will be able to add it back in by editing your details once you have registered

Since then, no spam bots. w00t. Of course, that forum only gets a handful of signups per year, so I don't really care if it inconveniences people slightly, it's primarily intended as a "private"ish (real life friends) forum anyway.

Re:Timing

[TheBogBrushZone]

Perhaps a solution is making the captcha time-intensive? If it takes an additional 30 seconds of 45 seconds, it might cut down on the number of captchas a person could solve in an hour.

Perhaps a long audio captcha with some intelligence required to prevent simple voice recognition "The first letter is Q. The second letter is V. Letter three is the letter after N. The fourth letter is the same as the second. The letter Z is not present".

Re:Unique Reg Form

[ahsile]

I had the same issue. I searched all over for some sort of blacklist plugin for phpbb to fix the issue, because i was just sick and tired of banning all sorts of domains every day. In the end, I ended up changing the website field to "hidden" on new user registration, and if the bots enter text into it... then I throw an error message.

The Anti-CAPTCHA

[TimTucker]

I've managed to cut down blog spam significantly lately after installing an Anti-CAPTCHA: http://www.timtucker.com/weblog/?p=74

The basic idea is to present a CAPTCHA image that's as easy for a machine to understand as possible and then ask the user to type in something else. (in the system that I'm using, users are presented with an unobscured image of a 6-digit number and asked to type in a different 6-digit number).

One of the great things about asking a user to type in something other than what's shown is that it's much more accessible than a regular CAPTCHA, since there's only a 1/1,000,000 chance that someone who can't see will accidentally type in the "right" six digit number.

Will solve CAPTCHAs for pr0n

[LauraW]

This talk on Google Video has a bit of info about CAPTCHAs. Apparently some porn sites are displaying occasional CAPTCHAs that their users have to solve before seeing the next page of porn, and then using these solved CAPTCHAs to spam blogs and other sites. The developers get bonus points for creativity, anyway.