User:AalekhN/GSoC proposal 2014


Multilingual, usable and effective Captchas[edit]

Name and contact information[edit]

Name:Aalekh Nigam
IRC or IM networks/handle(s):aalekhN
Location:New Delhi,India
Timezone: Kolkata,INDIA, UTC+5:30
Typical working hours:12:00PM to 2:00AM until August,05:00PM to 2:00AM after August (Indian Standard Time)


Current CAPTCHA's implemented in many Wikimedia Projects are mostly broken, lacks localization and are many times vulnerable. This project aims to design an Multilingual, usable and effective Captcha, which will be much more secure (difficult for bots to solve), user friendly (easier for humans to solve) and Multilingual for Mediawiki Projects.

Scope of Work[edit]

The Project aims to implement approach "Captcha for identifying Odd one out" for the Project. There are also some alternative approaches mentioned here. Also an Image Indexing System is planned to be developed which would improve the performance of the captcha system overtime.

Captcha for identifying Odd one out[edit]

The question of the given type of Captcha will be:

the answer to given Captcha is:

other possible questions for the Captcha's could be "Select the images in which man is wearing sunglasses?" as shown below:

If the Captcha combination gets wrong, Captcha reloads itself and shows the Captcha with different images. A demo representing Raw working prototype of the given type of captcha is

given here:

Advantage Over Bots  : Logical questions of "Selecting Odd One Out" is hard for bots to verify, also with the use of indexing 
system ( mentioned below) we can combine unrelated items as options; for example combining human and cat would be better option rather 
than combining Cat and Tiger's since the two resembles much alike.

Categories Selection for Images[edit]

In order to make categories unrelated we can make super-set of the categories for example:-> The categories of artist,astronauts can be categorized under the Super Category of humans, similarly collection of an array can be made comprising of unrelated categories such as “people”, “animals”, “machines" etc, moreover this array of unrelated categories can be modified by administrators of Wiki's to add more categories according to his need.

Captcha for Mobile Device[edit]

The Captcha for the mobile devices will be shown over as an overlay of mobile frontend over the page.

For the "Odd one out" type question the layout of the question will be as shown:

If the user click's on an wrong option all the image options of the captcha will be reloaded and a new Captcha question will be presented.

Image Indexing System[edit]

Since, for any project of mass scale to be successful requires localization; so for this project, I propose the use of an indexing system which would sort out the unjustified and irrelevant images out of those retrieved from Wikimedia Commons.

A simple functioning of indexing system I proposed is demonstrated here:

Proposal Image

Other Function of the Proposed Image Indexing System :[edit]

  • Prevent the reuse of images that are reloaded many number of type.
  • Provide options to the users that are closely not related to each other.
  • Provide User friendly effects to the images.


Indexing system is designed to improve overtime, thus providing user's with images that are globally acceptable and easily recognizable by humans.

Translation of question's asked in the captcha[edit]

Translation ( if needed ) for question used in Captcha can be performed by using .

Additional Note : Along with the ideas presented in the proposal, there are some other alternative alternative discussed in the notes page here.


The Project aims to develop an Captcha plugin for ConfirmEdit Extension with the use of Wikimedia Commons API, which would make WikiCommons act as a database for our Captcha images.

  • To Develop Plugin for current ConfirmEdit Extension.
  • Develop a proper indexing system for the images to be used for the Captcha which would sort out the images that are not friendly to the user.
  • If needed Develop effects for Captcha with the use of PHP's ImageMagick library, which makes images easily recognizable by humans but on the same time, makes captcha secure from bots. More explanation about Use of ImageMagick libray is given here.
  • Make Captcha Responsive to Mobile Devices
  • Use Wikimedia Commons API to retrieve images based on category of the images also translation to different words provided at Translate Wiki can help us make the Captcha Multilingual.

If Time Permits:

  • Improve audio Captcha for Blind and Visually Impaired users by introducing various new virtual cursors to the screen reader, which would help blind user's to reload the page.

Project schedule[edit]

  • Community bonding period.
    • Get familiar with WikiCommons API
    • Lay Down modular design for the project

Achieve the above by working with the mentor(s) and other community people interested in the project.

  • 3 weeks: Develop Captcha and integrate it with Wikimedia Commons API
    • Integrate WikiCommons Database with the Captcha using Wikimedia Commons API.
    • Develop Captcha for "Selection of Odd One Out" .

Milestone 1: Prototype for the extension ready.

  • 3-4 weeks:Develop Indexing System for the Captcha.
    • Develop an indexing System and integrate it with Prototype of the extension build .
    • Provide Localization Support to the Captcha.

Milestone 2: Indexing System build and Working.

  • 2 weeks: Port Captcha to Mobile Devices.
  • 1 weeks: Add unit test
  • 1 week: Ensuring proper integration and working with Mediawiki.
  • 2 weeks: Testing and documentation.

The above plan could go as expected or invariably re-distribute among the tasks.


As a regular follower to Mediawiki I regularly hangout at #mediawiki-i18n and #mediawiki and will continue to do so for period and beyond I am working. If face some doubts or needed advice i would head over to the mailing list. I will also post weekly update about the project on my blog about the project here. I will use a local environment for running MediaWiki for development and will be committing to Gerrit every feature i make on day to day basis. If needed i will host talk at

About Me[edit]

I am Aalekh Nigam, a B.Tech, Electronics and Communication Engineering student, in Jaypee Institute of Information Technology, Noida, India. Since, the introduction to FOSS at a local Linux User Group Meetup I have been mostly involved Web Development and Android App Development. As an advantage to this project I have worked with various image API's including that of Flickr and Instagram. My first interaction with MediaWiki started about five months ago when I started building an extension for MediaWiki. This projects holds an special importance for me since it would bring life of thousands of editors and Users in ease along with making Several Wiki's much more secure.

Past open source experience[edit]

Ever since my introduction to open source I have been an admirer to it and have worked with MediaWiki,WordPress,Flask frameworks.I'm an active contributor to Open Source Developers Club in my college and have helped in building website for open source conference organized by the club. Also,

I've also frequently attended various open source meetups including Software Freedom Day, local meetups of Linux User Group, Firefox, etc.

Any other info[edit]

Apart from which I also have been looking for various inspiration for audio Captcha and have found this specifically helpful.

Also several other approaches to complete the project are mentioned here.

Research Paper[edit]

Research Paper's that were helpful in preparing approaches of effective captcha as per mentioned in the proposal are given here:

Demo and Micro-task created for the project can be found on this page.