This document presents a proposal for an arithmetic and geometric CAPTCHA without a database. It discusses existing CAPTCHAs that use text, graphics, or puzzles but require large databases. The proposed scheme generates 3 random geometric shapes and a math operation for the user to perform without storing images. If answered correctly, it verifies the user is human. In conclusion, the database-less geometric CAPTCHA is secure and can be applied to real applications.

1. An Implementation of A Geometric and
Arithmetic CAPTCHA without Database
A Technical Seminar Presentation By
SHUBHAM SAURAV
(1DS12CS094)
Under Guidance Of:
Dr Arbind Gupta
(Professor)
Department Of Computer Science & Engineering

2. Contents
• Introduction
• Existing System
• Drawbacks
• The Proposed Scheme
• Conclusion
• References

3. CAPTCHA
• What is an CAPTCHA?
- A CAPTCHA -an acronym for "Completely
Automated Public Turing test to tell Computers
and Humans Apart"
• Why CAPTCHA?
- To prevent online polls
- Abusing free online accounts
- Spam e-mails

4. INTRODUCTION
• Nowaday, Internet require a CAPTCHA to identify the
user as a human or a bot to protect the system from
being damaged by the actions of bots.
• Few major concern with a CAPTCHA are:
i. CAPTCHA image has to be developed
ii. Database is required to store images used in
CAPTCHA

5. • Firstly we will create 3 random geometric
shapes.
• Secondly user will identify the desired shape
• Finally user will be asked to do a simple
calculation based on the captch image.

6. EXISTING SYSTEM
There are various kind of Captcha which are
currenty being used some of them are-
• Text based captcha
• Graphics based captcha
• Puzzle based captcha

7. Text based Captcha
• Very easy to implement
• Extremely efficient
• Necessitates a huge question bank
• No. of digits and character are limited

8. Graphics based Captcha
• User have to guess images
• Identify images with similarity
• It is a firm AI problem
• Hard to break

9. Puzzle based captcha
• A picture is divided into chunks
• The user is expected to join these chunks to form the
full picture similar to original one

10. TYPES OF GEOMETRIC CAPTCHA
• FAS captcha
In this type of captcha user looks at the number and do the required
arithmetic operations to give the desired result.

11. • Ironclad Captcha
This type of CAPTCHA image, showing various shapes to the user, and the
user answer the question based on these shapes

12. DRAWBACKS
• We need to develop a captcha image
• Images are usually large in size and takes large time
to load which decreases the effficiency.
• Chances of database being crashed

13. Proposed System
• Geometric CAPTCHA is developed with HTML5
and Java Script
• Does not require any database to store it
• user must enter the correct result into
the designated slot.

14. Conclusions
• This research presents an implementation of a
geometric and arithmetic CAPTCHA without
database .
• It uses an image showing three random geometric
shapes and a random two mathematical symbol.
• Then the user needs to convert the number of shapes
by numerical calculations that appear to put the
correct answer.
• A geometric and arithmetic CAPTCHA is safety and
can applied to real applications.

15. References
[1] S. Hocevar. (2014, Jan 10). PWNtcha-CAPTCHA decoder [Online].
Available: http://caca.zoy.org/wiki/PWNtcha
[2] K. Chellapilla, K. Larson, P. Y. Simard and M. Czerwinski, “Computers
beat humans at single character recognition in reading based human interaction
proofs (HIPs),” in proceedings of the 2nd conference on email and anti-spam.,
Stanford university. 2005.
[3] Red Hat Inc. (2014, Jan. 5). Sign up for a Fedora account [Online].
Available: https://admin.fedoraproject.org/accounts/user/new
[4] Security Stronghold. (2014, Jan. 4). Ironclad CAPTCHA [Online].
Available:http://www.securitystronghold.com/products/ironclad-captcha
[5] Google. (2014, Jan. 20). reCAPTCHA [Online]. Available:
http://www.google.com/recaptcha/learnmore
[6] S. Panhuber and M. Haudum. (2014, Jan 14). State of the art in
antiautomation technologies in today’s web [Online].

16. Thank You