How websites like Facebook are protected against bot without any captcha

Question

How websites like Facebook and Twitter are protected against bot during registration? I mean, there\'s no captcha at all on the signup form?

I want to create a signu

Answer 1

Well you can always deploy hardware solutions as well to create Layer 4-7 firewall rules. You can create specific rules to look for the well known agents of bots crawling the web. However to stop newly created bots you need to know what agent they are using for the bot.

Answer 2

Since you don't want CAPTCHA, you can use Keypic - keypic.com - which is an invisible protection, no CAPTCHA needed. It's an efficient antispam method for any web form. Site users don't pass any tests which is good for the site as it improves the quality of the user experience and thus raises user engagement. The solution is a kind of an expert system which analyses the behaviour of the users and checks the databases, then makes a conclusion if the request comes from a legitimate user or a robot. BTW, Twitter and Facebook still use CAPTCHA for password verification which is a very disputable method in terms of efficiency of such protection.

Answer 3

I had a problem with tons of bots signing up for my Nintendo site so I put a single image of Mario on the sign-up page (making sure nothing in the image data said "Mario") with the text "Who is this? Answer in one word." Haven't had a single bot sign-up since. Not sure if this is actually a good solution though, not sure how smart bots are. I'm kind of surprised that it worked.

In theory it might be keeping out a few legitimate users, but it is hard to imagine many legitimate users of a Nintendo site not knowing who Mario is...

Answer 4

Facebook uses some sort of hidden spam protection, if you view source of sign-up form you will see things like:

class="hidden_elem"><div class="fsl fwb">Security Check</div>This is a standard security test that we use to prevent spammers from creating fake accounts and spamming users.

so capture becomes visible when javascript will think that you are a bot.

Where is few methods of making it harder for bots to complete registration without capture, things like timing to fill out form, originators of mouse clicks events ect. also random session based values in form (to privent direct submissions without downloading of the form first)

also some people use hidden form elements with common names like 'email' that is styled invisible in css but common simple bots will try to fill out all form fields and so you can block them if this hidden element have any value

twitter and fb spend lot of time on developing tecniques to block spammers i don't think they will made it public as it will be counter productive for them to fight the spammers.

But all the client side javascripts you can download from fb or twitter and study them if you want, because most of the protection will happen inside client not on server.

server could only issue some random session variable, check for valid headers in request, overall time etc. its really limited.

some sites are also use ajax exchanges between server and client during the time when user is filling out the form , mostly just to make it harder for bot developer to do simular fake exchanges of data.

Anyway, unfortunatelly where is no easy solution to do decent protection , espesially without captcha or some kind of question

also, for submit button you can use image map instead of button, you can dynamically create big image with a submit botton image drawn on it at random position using things like GDI in PHP and using css to display only portion of that image with the actuall button, and on server side check X and Y position of where mouse was clicked, this will be hard for bots to break. Unless they use real browsers and just emulate keyboard and mouse. Anyway , as i said unfortunatelly where is no easy solution.

Answer 5

I don't know how Facebook and Twitter do it, but if you want to create something simple and that doesn't interfere with your site aesthetics, I know that some websites just ask the user to enter an answer to a simple math problem like "what is 2 + 3?". This is not the most secure way to do it, but it's just a thought.

Answer 6

One way would be to send a verification to the user's email address or cell phone and obtain verification (so in that case, you would have to allow only one email address or cell phone per account)

Another option is to use "Negative CAPTCHA" or "Honeypot Captcha"