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Method and System for Identifying Legitimate Users via Personalized CAPTCHAs

IP.com Disclosure Number: IPCOM000199151D
Publication Date: 2010-Aug-27
Document File: 2 page(s) / 79K

Publishing Venue

The IP.com Prior Art Database

Related People

Anirban Dasgupta: INVENTOR [+3]

Abstract

A method and system for identifying legitimate users using personalized CAPTCHAs is disclosed. The method personalizes the CAPTCHAs for users that are being tested based on an activity performed by the users.

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Method and System for Identifying Legitimate Users via Personalized CAPTCHAs

Abstract

A method and system for identifying legitimate users using personalized CAPTCHAs is disclosed.  The method personalizes the CAPTCHAs for users that are being tested based on an activity performed by the users.

Description

Disclosed is a method and system for identifying legitimate users using personalized CAPTCHAs.  The method and system proposes to use harder CAPTCHAs, for example, with more distortion to identify legitimate users.  CAPTCHAs are personalized based on a user who is being tested.  As a result, the personalized nature of CAPTCHAs makes it easier for legitimate users to solve them while ensuring that robots and paid humans find it difficult to solve them.  The method may be applied in situations where some kind of activity has been observed by users.

The method and system constructs CAPTCHA puzzles based on the words used or seen by the user as a result of some activity which is performed by the user.  For example, if it has been observed that the user has sent an email to a contact, then the name of the contact may be used as the character string in the CAPTCHA.  As another example, in situations where an account is being used by a robot for spamming, the method can use highly repetitive word from email subjects as the CAPTCHA string.

Moreover, the CAPTCHAs may be distorted to a much higher degree than normal since the legitimate user should still be able to decipher the CAPTCHAs as the user is already familiar with the word.  Subsequently, automated systems and h...