Image encryption and decryption with residual intelligibility measurements
Dissertant
Thesis advisor
Comitee Members
al-Ajluni, Naim M. M.
Ammar, Man
Muhammad, Sarmad B.
University
Arab Academy for Financial and Banking Sciences
Faculty
The Faculty of Information Systems and Technology
Department
Computer information systems
University Country
Jordan
Degree
Ph.D.
Degree Date
2005
English Abstract
The use of images has increased dramatically in recent years especially with Internet applications.
When it is necessary to securely transmit data in open networks, the encryption must be performed.
Most of the cryptographic algorithms were mainly developed for text data.
Unfortunately, algorithms those are good for textual data might not suitable for multimedia data.
We tested the most known modes of encryption (ECB, CBC, CFB, and OFB) to encrypt images of different types (satellite and photo images).
Results showed that the ECB mode achieved the lowest degree of encryption with a mean entropy value of 7.78, while both of CFB and CBC modes achieved the highest degree of encryption with a mean entropy value of about 7.98 and 7.96, respectively.
The OFB mode achieved a mid-range level of encryption with a mean entropy value of 7.93.
In addition, factors that effect on encryption level were determined.
Furthermore, we proposed a new algorithm for image encryption in which a secure encryption algorithm was used to encrypt the image, suc that it is difficult to decode or predict the ciphered image to the original image.
The experimental results showed that the proposed algorithm has confusion and diffusion properties in a way that it did not contain any useful information about the plane image.
The similarity decreased to about 51 % by applying the second step of the proposed algorithm, while, the mean correlation between neighbor pixels decreased dramatically from 90 % to about 8 % by applying the third step.
The proposed algorithm has the ability to restore the original image in a 99.9 % of similarity.
I we proposed a new scheme to generate keys from the image data.
The degree of the randomness of the generated sequences was measured by using five statistical tests.
The experimental results showed that 79 % of the generated sequences passed all randomness constraints, whereas, at least 94 % of the cases passed at least four tests.
Results showed that the degree of encryption increased as the randomness level increased, especially by using the ECB mode with which the entropy value increased from 7.2 to 7.9 for different randomness level.
Main Subjects
Information Technology and Computer Science
Topics
No. of Pages
192
Table of Contents
Table of contents.
Abstract.
Chapter One : introduction and literature survey.
Chapter Two : image encryption : concepts snd methodologies.
Chapter Three : image encryption by using different modes.
Chapter Four : a higher degree of image encryption by using wavelet transform.
Chapter Five : random-bit sequence generation from image data.
Chapter Six : conclusions and future works.
References.
American Psychological Association (APA)
Jarrar, Hashim Jamil. (2005). Image encryption and decryption with residual intelligibility measurements. (Doctoral dissertations Theses and Dissertations Master). Arab Academy for Financial and Banking Sciences, Jordan
https://search.emarefa.net/detail/BIM-316168
Modern Language Association (MLA)
Jarrar, Hashim Jamil. Image encryption and decryption with residual intelligibility measurements. (Doctoral dissertations Theses and Dissertations Master). Arab Academy for Financial and Banking Sciences. (2005).
https://search.emarefa.net/detail/BIM-316168
American Medical Association (AMA)
Jarrar, Hashim Jamil. (2005). Image encryption and decryption with residual intelligibility measurements. (Doctoral dissertations Theses and Dissertations Master). Arab Academy for Financial and Banking Sciences, Jordan
https://search.emarefa.net/detail/BIM-316168
Language
English
Data Type
Arab Theses
Record ID
BIM-316168