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Article
Generate Animated CAPTCHA Based on Visual Cryptography Concept

Authors: Akbas E. Ali --- Nidaa F. Hassan --- Matheel Emad EL-Deen Abdulmunim
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2011 Volume: 29 Issue: 16 Pages: 3405-3416
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

CAPTCHA is a standard security technology. To date, the most commonly used are various types of visual CAPTCHAs, in which a challenge often appears as an image of distorted text that the user must decipher. The proposed scheme is used visual cryptography encryption protocol to encrypt CAPTCHA image in perfectly secure way, such that only the human visual system can easily decrypt the CAPTCHA image with animated arrangement. Numbers of blurring image process are implemented on the CAPTCHA images, to make this test difficult for current computer systems. The new animated CAPTCHA is more secure than the currentversions and easier for humans to pass.


Article
Propose Image Captcha System
اقتراح نظام صورة كلمة التحقق

Authors: Rajaa K .Hasoun رجاء كاظم حسون --- Soukaena H. Hashem سكینة حسن ھاشم --- Rehab F. Hasan رحاب فلیح حسن
Journal: AL-MANSOUR JOURNAL مجلة المنصور ISSN: 18196489 Year: 2016 Issue: 26 Pages: 85-100
Publisher: Private Mansour college كلية المنصور الاهلية

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Abstract

Captcha has been designed to be easy for humans and hardon the machines. Captcha are used by many websites to determinehuman users from indecent programs. This paper will propose two typesfor generating captcha these are; text and image captcha. In the first typeuse (6*6) captcha table to store alphabetic characters 'A'..'Z' and '0'..'9'and use random function to generate six numbers to represent the rowand colum numbers which used as index to retrieve the character fromthe captcha table to get the final captcha. In the second types a sample of100 images from PayPal.com Human Interactive Proofs (HIP) are used. Inorder to recognize these images three steps for recognize the characters(pre-processing, segmentation and classification) are adopted. Themodification was in the preprocessing step where proposing to useGabor filter to remove the noise in the images which make the recognitionaccuracy 100% which is good results when compared with the obtainedaccuracy in reference [1] where the accuracy value in the range (80% ..98%) for different scheme used in this work.

كلمة التحقق صممت لتكون سھلة للبشر لكن صعبة للمكائن. كلمة التحقق تستخدم من قبل المواقعلتحدید البرامج غیر اللائقة من المستخدمین البشر الحقیقیین . في ھذا البحث سوف نقترح طریقتین لتولید6 ) لخزن الاحرف والأرقام * صورة كلمة التحقق: النص والصورة. في النوع الاول تم استخدام جدول ( 6وكذلك تم استخدام دالة عشوائیة لتولید ستة ارقام تمثل ارقام الصفوف والأعمدة وتستخدم كمؤشرلاسترجاع الاحرف من الجدول للحصول على كلمة التحقق النھائیة. في النوع الثاني تم استخدام عینةثلاث خطوات لتمییز الاحرف تم , PayPal.com تتكون من 100 صورة المستعملة في موقعاستخدامھا، وھي (المعالجة الاولیة ، التقطیع والتصنیف). التحدیث تم في خطوة المعالجة الاولیة حث تماستخدام فلتر كابور لإزالة الضوضاء من الصور مما جعل دقة التمییز تكون 100 % وھي نتائج جیدة عند. % مقارنتھا مع النتائج في المصدر رقم ( 1) حیث ان قیمة الدقة تتراوح بین 80 % الى 9


Article
Propose an Arabic CAPTCHA System based on Chaotic Maps

Authors: Mariam T. Sulaiman --- Nidaa F. Hassan
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2018 Volume: 36 Issue: 1 Part (B) Scientific Pages: 48-52
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

CAPTCHA is the facility that prevents web bots from accessingthe web services by generating tests to check whether the user is human orcomputer program. In this paper, a new pseudo-random bits generator basedon chaotic system is offered to generate Arabic letters and numbers forCAPTCHA system. The proposed generator uses two Jacobian ellipticChebyshev rational maps that are combined in the algorithm to produce ablock of 32bits in each iteration. A specified number of bits are selected fromthe resulted blocks to be converted to a set of Arabic letters and numbers.National Institute of Standards and Technology (NIST) statistical test suiteare used to assess the generator randomness, all tests has been passed exceptLongest Run of Ones in a Block Test, Binary Matrix Rank Test and RandomExcursions Test.


Article
Secure online form with Advanced CAPTCHA Code Technique the Practice and Theory

Author: Wafaa M.A. Alkhefaji
Journal: Journal of Education for Pure Science مجلة التربية للعلوم الصرفة ISSN: 20736592 Year: 2017 Volume: 7 Issue: 4 Pages: 139-149
Publisher: Thi-Qar University جامعة ذي قار

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Abstract

AbstractAs we know that internet is being utilized for several activities by a great range of users andtheseactivities include communication, e-commerce, edification, education and regalement. Users arerequired to register regarding to a website in order to enroll web activities. However, registration canbe done by automated hacking software. That software make erroneous enrollments which occupythe resources of the website by reducing the performance and efficiency of servers, even stop theentire web accommodation. It is critical for the websites to possess a system that has the inclinationof varying human users and computer programs in perusing pictures of content.ConsummatelyAutomated Public Turing Test to Tell Computers and Human Apart (CAPTCHA) is a technique thatprotects websites against bots by generating and grading tests that humans can pass but currentcomputer programs cannot. For example, humans can read distorted text, but current computerprograms cannot. This study focuses on the CAPTCHA abilities of defensing a website fromscammers by discussion its algorithm and practical steps to apply it in a web form.

Keywords

Keywords: CAPTCHA --- Security --- Website --- Forms --- Online --- Spam --- Bots --- Hack --- PHP --- Application

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