Research Journal of Applied Sciences, Engineering and Technology 9(11): 969-981, 2015 ISSN: 2040-7459; e-ISSN: 2040-7467 © Maxwell Scientific Organization, 2015 Submitted: October 29, 2014 Accepted: December 18, 2014 Published: April 15, 2015 Corresponding Author: Lahieb Mohammed Jawad, UTM-IRDA Digital Media Center (MaGIC-X), Faculty of Computing, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia 969 Classification of Novel Selected Region of Interest for Color Image Encryption 1, 2 Lahieb Mohammed Jawad and 1 Ghazali Sulong 1 UTM-IRDA Digital Media Center (MaGIC-X), Faculty of Computing, Universiti Teknologi Malaysia, 81310 Skudai, Johor, Malaysia 2 Department of Network Engineering, College of Information Engineering, Al-Nahrain University, Baghdad, Iraq Abstract: Securing digital image in exchanging huge multimedia data over internet with limited bandwidth is a significant and sensitive issue. Selective image encryption being an effective method for reducing the amount of encrypted data can achieve adequate security enhancement. Determining and selecting the region of interest in digital color images is challenging for selective image encryption due to their complex structure and distinct regions of varying importance. We propose a new feature in acquiring and selecting Region of Interest (ROI) for the color images to develop a selective encryption scheme. The hybrid domain is used to encrypt regions based on chaotic map approach which automatically generates secret key. This new attribute is a vitality facet representing the noteworthy part of the color image. The security performance of selective image encryption is found to enhance considerably based on the rates of encrypted area selection. Computation is performed using MATLAB R2008a codes on eight images (Lena, Pepper, Splash, Airplane, House, Tiffany, Baboon and Sailboat) each of size 512*512 pixels obtained from standard USC-SIPI Image Database. A block size of 128*128 pixels with threshold levels 0.0017 and 0.48 are employed. Results are analyzed and compared with edge detection method using the same algorithm. Encrypted area, entropy and correlation coefficients performances reveal that the proposed scheme achieves good alternative in the confined region of interest, fulfills the desired confidentiality and protects image privacy. Keywords: Block cipher, chaotic map, hybrid domain, ROI, selective image encryption, vitality feature INTRODUCTION Lately, the exponential escalation in multimedia technology and exhaustive exploitations of internet in transmitting and storing gigantic amount of digital data with limited bandwidth and small storage capacity posed substantial threat towards data security and safety. Images being the widely used multimedia information in assorted fields of applications demand secured transmission (Rehman et al., 2014). Image Encryption (IE) is an established technique that is used to keep image safety. The rationale of developing a precise IE scheme is to modify the original image by encoding it in such a way so that it appears non-understandable for unauthorized users. In short, the idea of encryption is to ensure the utter secrecy via data conversion into a form called a ciphertext. Usually, IE requires vast amount of processing requirements which is ever-demanding for an efficient solution (Ullah et al., 2013). Consequently, efforts are dedicated to remarkably reduce the encrypted digital contents via the Selective Image Encryption (SIE) that only encrypts a part of the image (Puech et al., 2013). The fundamental concept of SIE is based on analyzing and identifying the significant and insignificant image regions followed by the encryption of significant areas (Hoang and Tran, 2014; Metzler and Agaian, 2010). In fact, occurrence of a tiny error in the significant part causes substantial change in the image. Conversely, slight modifications in the insignificant part does not induce much effect on the image (Bhatnagar and Jonathan Wu, 2012). Moreover, the encrypted parts in SIE scheme must be independent of the unencrypted parts (Suresh and Madhavan, 2012). Figure 1 illustrates the general architecture of SIE system consisting of two main phases such as selected and encrypted ROI. The successful implementation of selective encryption relies on the sizeable reduction in the amount of encrypted area producing satisfactory security level. Subsequently, different encryption algorithm in spatial and frequency domains are developed (Jawad and Sulong, 2013). Nevertheless, ROI based algorithm are limited in determining the correct region of interest because each image use different criteria for determining ROI (Dutta and Chaudhuri, 2009). Therefore, feature extraction that decides the ROI requires further improvement. Furthermore, most of the SIE techniques based on the encrypted area as significant region fail to satisfy the requirements for high security level (Steffi and Sharma, 2011; Puech et al., 2013).