How @ITweetBio Authenticates You

@ITweetBio lists Twitter bios and regularly tweets from the list. You can enlist your Twitter bio there. @ITweetBio wants to make it easy for you to enlist your bio without requiring you to register yourself with the service, or making you to authenticate the application. You are already known in Twitter by your handle. You can just give your Twitter handle like @BlindTalk, and @ITweetBio will use the handle to read your bio from Twitter and enlist it. However, anyone can give your Twitter handle to @ITweetBio acting like he is you. @ITweetBio wants to verify that you are the one who gives the handle, not anyone else.

I wrote a short article almost three years ago on Authentication by Mentioning using Twitter but I didn't give any sample code. I am going to give a sample code at the end of this article. I found it easy to authenticate someone using only his Twitter account. All he has to do is tweet a specific message from me and I will read his Twitter status that must match with the message. Obviously only he can do the tweet from his Twitter account. However, his Twitter time line must be made public so that I can read his status without using any credential. If he makes his time line private then I have to be his follower first, that he has to allow me reading the time line.

@ITweetBio assumes that your Twitter time line is public. You are required to tweet a bio from the list. Once you have tweeted, @ITweetBio will read your last Twitter status looking for the same bio. If they are matched then you are authenticated and your bio will be enlisted.

Imagine that your Twitter bio is already enlisted and at the same time someone else wants his bio also to be enlisted. The person will be asked to tweet probably your bio and he does it. Thus, your bio is also tweeted by someone else other then a potential tweet by @ITweetBio. Asking someone to tweet bio serves two purposes—to authenticate and to get bios to be tweeted.

The Code

The following is the PHP code to read someone Twitter status given the handle:

function read_status($handle)

{

  $user = json_decode(

    file_get_contents(

      "https://api.twitter.com/1/users/show.json?screen_name=$handle"));

  if (isset($user->status) && isset($user->status->text))

    return $user->status->text;

  return FALSE;

}

Note that you don't want to be querying Twitter only for the user status since the $user object contains many other information. The user bio is also returned with the same query.