231 research outputs found

    Hybrid chaotic map with L-shaped fractal Tromino for image encryption and decryption

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    Insecure communication in digital image security and image storing are considered as important challenges. Moreover, the existing approaches face problems related to improper security at the time of image encryption and decryption. In this research work, a wavelet environment is obtained by transforming the cover image utilizing integer wavelet transform (IWT) and hybrid discrete cosine transform (DCT) to completely prevent false errors. Then the proposed hybrid chaotic map with L-shaped fractal Tromino offers better security to maintain image secrecy by means of encryption and decryption. The proposed work uses fractal encryption with the combination of L-shaped Tromino theorem for enhancement of information hiding. The regions of L-shaped fractal Tromino are sensitive to variations, thus are embedded in the watermark based on a visual watermarking technique known as reversible watermarking. The experimental results showed that the proposed method obtained peak signal-to-noise ratio (PSNR) value of 56.82dB which is comparatively higher than the existing methods that are, Beddington, free, and Lawton (BFL) map with PSNR value of 8.10 dB, permutation substitution, and Boolean operation with PSNR value of 21.19 dB and deoxyribonucleic acid (DNA) level permutation-based logistic map with PSNR value of 21.27 dB

    Encrypting an audio file based on integer wavelet transform and hand geometry

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    A new algorithm suggested for audio file encryption and decryption utilizing integer wavelet transform to take advantage of the property for adaptive context-based lossless audio coding. In addition, biometrics are used to give a significant level of classification and unwavering quality because the procedure has numerous qualities and points of interest. The offered algorithm utilized many properties of hand geometry estimations as keys to encode and decode the audio file. Many tests were carried out on a set of audio files and quality metrics such as mean square error and correlations were calculated which in turn confirmed the efficiency and quality of the work

    Speech Steganography System Using Lifting Wavelet Transform

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    This paper presents a new lossless speech steganography approach based on Integer-to-Integer Lifting Wavelet Transform (Int2Int LWT) and Least Significant Bits (LSBs) substitution. In order to increase the security level a simple encryption with chaotic key has been proposed. The proposed system has a high sensitivity in choosing keys because a small change in CKG causes a new secret key for transmitting. Speech steganography algorithm that based on (Int2IntLWT) can satisfy full recovery for the embedded secret messages in the receiver side. Keywords:Speech steganography, information hiding, Int2Int LWT, (LSB) technique, XOR operation

    A Color Image Watermarking Scheme Based On QR Factorization, Logistic and Lorentz Chaotic Maps

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    Most of the existing color image watermarking schemes use grayscale or binary image as watermark because color image watermark has more data than grayscale or binary watermark. Therefore, it is a challenging issue to design a color image-watermarking scheme. This paper proposes a novel color image watermarking scheme to embed color image watermark into color host image. In watermarking schemes, first divide the host and watermark image into non-overlapping blocks, apply the Discrete Cosine Transformation (DCT) on each blocks of both watermark, and host image. After that QR Factorization, apply on the each blocks of watermark. In this paper, Logistic and Lorentz chaotic maps are usedfor estimating the embedding strength and location. The experimental results reveal that this watermarking scheme is robust against different image processing attacks viz. cropping, contrast adjustment and coloring

    A new partial image encryption method for document images using variance based quad tree decomposition

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    The proposed method partially and completely encrypts the gray scale Document images. The complete image encryption is also performed to compare the performance with the existing encryption methods. The partial encryption is carried out by segmenting the image using the Quad-tree decomposition method based on the variance of the image block. The image blocks with uniform pixel levels are considered insignificant blocks and others the significant blocks. The pixels in the significant blocks are permuted by using 1D Skew tent chaotic map. The partially encrypted image blocks are further permuted using 2D Henon map to increase the security level and fed as input to complete encryption. The complete encryption is carried out by diffusing the partially encrypted image. Two levels of diffusion are performed. The first level simply modifies the pixels in the partially encrypted image with the Bernoulli’s chaotic map. The second level establishes the interdependency between rows and columns of the first level diffused image. The experiment is conducted for both partial and complete image encryption on the Document images. The proposed scheme yields better results for both partial and complete encryption on Speed, statistical and dynamical attacks. The results ensure better security when compared to existing encryption schemes

    A Non-Blind Image Watermarking Method for Copyright Protection

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       في هذا البحث ، تم تقديم طريقة العلامة المائية غير العمياء لحماية حقوق النشر الخاصة بالصور الرقمية الملونة. تعتمد هذه الطريقة على مجموعة من التحويلات الرقمية (DWT ، DCT) في مجال التردد. تعتمد عملية التضمين في هذه الطريقة على تقسيم الصورة المضيفة إلى كتل غير متراكبة 16 × 16 واستخدام مقياس إنتروبيا الحافة لاختيار الكتل المناسبة لعملية التضمين لزيادة عدم الإدراك في النظام المقترح. أما بالنسبة لعملية الاستخراج ، فهي تتم بطريقة تتطلب وجود الصورة الأصلية ولكنها تتبع نفس بروتوكول التضمين لاستخراج العلامة المائية المشفرة المضمنة . و لرفع مستوى الأمان ، تم تطبيق طريقة تشفير هجينة باستخدام الخريطة الفوضوية وترميز الحمض النووي لتشفير العلامة المائية قبل تضمينها. تظهر النتائج التجريبية أن الاختلافات بين الصورة ذات العلامة المائية والصورة الأصلية لا يمكن تمييزها. الطريقة المقترحة قاومت بشكل فعال هجمات معالجة الصور الشائعة.    In this paper, a non-blind watermarking method for protecting the copyright of digital color images is introduced. This method based on the combination of digital transforms (DWT, DCT) in the frequency domain. The embedding process in this method depends on the partition of the host image into 16×16 non-overlapped blocks and the use of edge entropy metric to choose the appropriate blocks for the insertion process for the purpose of increasing the imperceptibility of the proposed system. As for the extraction process, it is carried out in a way that requires the presence of the original image but rather follows the same embedding protocol to extract the embedded encrypted watermark. To raise the security level, a hybrid encryption method using the chaotic map and DNA coding has been applied for encrypting the watermark before embedding it. Experimental results demonstrate that the differences between the watermarked image and the original image are indistinguishable. The proposed method is effectively resisted common image processing attacks
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