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Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
Human or Intelligent Machine?
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Human or Intelligent Machine?

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Concept of ANN and Proposal of new CAPTCHA

Concept of ANN and Proposal of new CAPTCHA

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Transcript

  • 1.
    • Concept of Neural Networks
    • Towards
    • Breaking CAPTCHA
    • And the introduction of 3D CAPTCHA
    • Ameya Kulkarni
    • Ruhi Kulkarni
    • Ankit Navlakha
  • 2. How The Brain Learns ?
    • Structure of brain
    • Establishment of Neural Pathways
    • Readjustment of parameters to incorporate discrepancies in data.
  • 3. Biological Neuron
    • Collects signals through dendrites.
    • Soma processes these signals and sends out a spike to the axon depending upon a threshold.
    • The axon is connected to inputs of other neurons through Synapses.
    • Learning occurs by adjusting the synaptic weights.
  • 4. What is a Neural Network?
    • Definition: An Artificial Neural Network (ANN) is a computing paradigm that can recognize patterns in a given collection of data and produce a model for that data. It resembles the brain in two respects:
      • Knowledge is acquired by the network through a learning process (trial and error).
      • Interneuron connection strengths known as synaptic weights are used to store the knowledge.
  • 5. Neural Network Structure
    • Artificial neuron
    input output
    • An ANN is a set of processing elements (PEs) and connections with adjustable strengths (weights)
  • 6. How Do Neural Networks Work?
    • Train the Network:
    • 1. Present data to the network
    • 2. Network computes an output
    • 3. Network output compared to desired output
    • 4. Network weights are modified to reduce error
    • Use the Network:
    • 1. Present new data to the network
    • 2. Network computes an output based on its training
    input output
  • 7. Undistorted image (Training mode) :
  • 8. Distorted image (Working mode) :
  • 9. CAPTCHA
    • Completely Automated Public Turing Test to tell Computers and Humans Apart.
    • Turing test
    • Distorted text that appears when any new account has to be created.
    FCZH solution
  • 10. Application After every poll voter has to pass the CAPTCHA test. Online Polls The idea is to require users to solve a CAPTCHA before showing your email address. Protecting Email Addresses From Scrapers To use CAPTCHAs to ensure that only humans obtain free accounts . Protecting Website Registration Proposed Solution Application Area
  • 11. Breaking Captcha
    • Other techniques like the OCR, Standard dictionary attack, segmentation have shown upto 35% accuracy.
    • Using the Neural Network pattern recognition technique an attempt can be made to break the Captcha.
    • Greater accuracy will be achieved using this method.
    • This would make all the sites today which use this textual CAPTCHA vulnerable to attack.
  • 12. Proposing a 3D Captcha
    • Manually generate a library of 3D objects
  • 13.
    • The computer is given a description of each attribute of each object.
  • 14.
    • Now the remaining process is fully automated.
    • The computer randomly picks any objects from the library and they are placed together in a scene.
  • 15.
    • The individual attributes are labeled with characters.
    • The computer is given a set of characters to encode.
    • The computer will then list the attributes that correspond to the characters of the sub-address that is being encoded.
  • 16. An Example
    • Please click on or enter each letter corresponding to the following list in the field below. You must enter them in the exact sequence listed. • The Head of the Walking Man • The Vase • The Back of the Chair
  • 17. Conclusion
    • Thus, Neural network pattern recognition technique concept can be used in breaking the CAPTCHA.
    • The new from of 3D Captcha would be invulnerable to such technique.
  • 18. Thought for the Future….
    • Thus, as the machine intelligence increases with biologically inspired computing methods, the need for tougher and tougher CAPTCHA’s arises.
    • So , don’t be surprised if one day you cannot create your email account, because you are no more intelligent enough.
  • 19. References
    • Artificial Intelligence by Elaine Rich and Kevin Knight.
    • Artificial Neural Networks in Real-life Applications -by Juan Ramon Rabunal, Julian Dorrado.
    • spamfizzle.com/CAPTCHA.aspx
    • www.captcha.net/
  • 20. THANK-YOU.

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