Has anyone used reCaptcha on their iPhone application? I am trying to figure out how to embed it in my App...
+7
A:
Why in the name of Bob would you do that?
I think it's a fair assumption that when someone is accessing your application from an iPhone, they are human.
Edit: You do know that this is the purpose of a Captcha, right? Verifying sapience?
Williham Totland
2010-03-15 13:40:01
+1 for sapience :D
Jasarien
2010-03-15 16:17:49
I want to do this because for example someone who signs up on the iPhone to my website, they are human but what if a hacker uses the http protocol sign up string and spams my website? I guess a work around is to know the request is coming from an iphone. How do you check for that?
Erika
2010-03-15 18:55:55
You can add a (random) secret to your request, and (optionally) connect with SSL. In short, have some bit of code that generates a unique identifier that (with high likelyhood) comes from the iPhone app; so that each request becomes unique, and spoofing it becomes non-trivial.
Williham Totland
2010-03-15 19:58:56
(A difficult one to breach would be a secret concatenated with the current time and securely hashed (SHA256 should do the trick). Just be sure to send the current time from the device along.)
Williham Totland
2010-03-15 20:01:23
Another trick to make it even safer is to use some insane date format for stringifying the date before concatenation, and sending the date along to the server on a sane format: `sha256("secret" CAT "MM/DD/YY")` => server, along with YYYYMMDDYHHMMSS
Williham Totland
2010-03-16 08:32:42
Thanks Williham totland, you have some great ideas! I ended up using the last suggestion you made.
Erika
2010-04-09 16:47:51
@user280556: you did remember to replace "secret" with an actual secret, right?
Williham Totland
2010-04-09 22:03:47
A:
you guys are really talking about digest authentication. There are valid reasons for making the iphone use recaptcha. I need a solution for this myself :(
Richard
2010-06-11 12:28:59
A:
The only way to use reCaptcha in an iPhone app is by rendering a WebView within the app. There is a nice alternative to reCaptcha called kaptcha that actually has a usable api. http://code.google.com/p/kaptcha/
Sasi
2010-07-14 00:54:33