A Novel Technique for Secure Data Cryptosystem Based on Chaotic Key Image Generation

أحدثت التطورات في تكنولوجيا المعلومات والاتصالات، خلال العقود الماضية، تغييراً كبيراً في نمط نقل معلومات الأشخاص عبر الإنترنت/الشبكات أو تخزينها. لذا، فإن أحد التحديات الرئيسية هو الحفاظ على هذه المعلومات بصورة آمنة ضد الهجمات. أدرك العديد من الباحثين والمؤسسات أهمية وفوائد التشفير في تحقيق الكفاءة والفاعلية بمختلف جوانب الاتصال الآمن.يتبنى هذا العمل تقنية جديدة لنظام تشفير البيانات الآمن على أساس نظرية الفوضى. تولد الخوارزمية المقترحة مصفوفة مفاتيح ثنائية الأبعاد لها ذات أبعاد الصورة الأصلية والتي تتضمن أرقاما عشوائية تم الحصول عليها من الخريطة الفوضوية اللوجستية أحادية الأبعاد وفق معطيات معاملات التحكم، والتي تتم معالجتها بعد ذلك من خلال تحويل الأجزاء العشرية منها عن طريق دالة إلى مجموعة من الأرقام غير المتكررة التي تؤدي إلى عدد هائل من الاحتمالات الغير قابلة للتوقع (مفكوك ناتج ضرب الصفوف في الأعمدة). يتم إجراء بعثرة مزدوجة للصفوف والأعمدة لقيم الأرقام لعدد محدد من المراحل. بعد ذلك، يتم تنفيذ عمليات XOR بين مصفوفة المفاتيح والصورة الأصلية، والتي تمثل حلاً فعالاً لتشفير البيانات لأي نوع من الملفات (النصية، الصورية، الصوتية، الفيديوية، ... إلخ).أثبتت النتائج أن تقنية التشفير المقترحة تعتبر جدا واعدة وفقا لمعايير القياسات الأمنية حيث أدت إلى تسطيح Histogram للصور المشفرة مقارنة بما هو عليه بالصور الأصلية، في حين أن متوسطات MSE عالية جدا (10115.48) و PSNR منخفضة جدا (8.17)، إلى جانب مؤشر Correlation هو قريب من الصفر و Entropy القريبة من 8 (7.997).The advancements in Information and Communication Technology (ICT), within the previous decades, has significantly changed people’s transmit or store their information over the Internet or networks. So, one of the main challenges is to keep these information safe against attacks. Many researchers and institutions realized the importance and benefits of cryptography in achieving the efficiency and effectiveness of various aspects of secure communication.This work adopts a novel technique for secure data cryptosystem based on chaos theory. The proposed algorithm generate 2-Dimensional key matrix having the same dimensions of the original image that includes random numbers obtained from the 1-Dimensional logistic chaotic map for given control parameters, which is then processed by converting the fractional parts of them through a function into a set of non-repeating numbers that leads to a vast number of unpredicted probabilities (the factorial of rows times columns). Double layers of rows and columns permutation are made to the values of numbers for a specified number of stages. Then, XOR is performed between the key matrix and the original image, which represent an active resolve for data encryption for any type of files (text, image, audio, video, … etc). The results proved that the proposed encryption technique is very promising when tested on more than 500 image samples according to security measurements where the histograms of cipher images are very flatten compared with that for original images, while the averages of Mean Square Error is very high (10115.4) and Peak Signal to Noise Ratio is very low (8.17), besides Correlation near zero and Entropy close to 8 (7.9975)

Evaluation of the quality of an image encrytion scheme

Encryption systems have been developed for image viewing applications using the Hill Cipher algorithm. This study aims to evaluate the image encryption quality of the Hill Cipher algorithm. Several traditional metrics are used to evaluate the quality of the encryption scheme. Three of such metrics have been selected for this study. These include, the Colour Histogram, the Maximum Deviation (comparing the original image) and the Entropy Analysis of the encrypted image. Encryption quality results from all three schemes using a variety of images show that a plain Hill Cipher approach gives a good result for all kinds of images but is more suited for colour dense images

NEW HIDING TECHNIQUE IN DIGITAL SIGNATURE BASED ON ZIGZAG TRANSFORM AND CHAOTIC MAPS

Abstract This paper presents a novel approach to digital signature by integrating the ElGamal or Schnorr digital signature algorithms, chaotic systems, and scanning techniques. Briefly, ZZBCRP is a zigzag transformation that is used firstly to construct a permuted transaction, which technique starts from any random position and intersects in both directions, which is more complex than zigzag transform techniques. Then using ElGamal or Schnorr signature schemes based on chaotic maps. This modification aims to make private key and random number dependent on discrete chaotic maps. Even if the private key chosen is small, it is easy by using the huge amount of points in chaotic maps 2-D or 3-D to extract strong and unique key. This change complicates the relationship between the private key, public key and the transaction signature. A two-dimensional trigonometric discrete chaotic map is used that integrated Logistic-sine-cosine maps, and a three-dimensional hyperchaotic map (3-D SCC) which are based on a sine map. Our performance analysis shows that compared to schemes; this scheme not only improves the level of efficiency but also assures safety. The performance analysis shows that our scheme is not only more efficient compared to other related systems, but also safer

Criptografia baseada em caos : aplicação usando um sistema hipercaótico

Trabalho de conclusão de curso (graduação)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2019.Neste trabalho se propõe um esquema para telecomunicação segura baseado na sincroni zação de um sistema nonodimensional hipercaotico e analise de Lyapunov. Ao contrário da maioria dos esquemas usualmente encontrados na literatura, o esquema proposto requer apenas que o controle atue em uma das equações de estado do sistema escravo. Foi verificada mate maticamente a convergência do erro de sincronização para um conjunto compacto arbitrário, permitindo-se obter um erro convergente a uma vizinhança da origem. Com um circuito caótico transmissor (ou mestre) codifica-se o sinal (ou mensagem) e com outro circuito caótico receptor (ou escravo) recupera-se a mensagem. O esquema proposto tem como vantagens ser robusto contra perturbações (internas e externas) e ser estruturalmente simples, quando comparado com as propostas existentes na literatura, o que é importante, uma vez que leva a redução de custos quando implementado utilizando eletrônica analógica. Para validar a robustez e simplicidade do esquema proposto, simulações computacionais utilizando software MATLAB/Simulink foram realizadas.This work proposes a scheme for secure telecommunication based on the synchronization of a hyperchaotic system and Lyapunov analysis. Unlike most schemes usually found in the literature, the proposed scheme only requires that the control act on one of the slave state equa tions. The convergence of the synchronization error to an arbitrary compact set was verified mathematically, allowing a convergent error to be arbitrarily small neighborhood of the origin. With a transmitting (or master) chaotic circuit the signal (or message) is encoded and with another receiving (or slave) chaotic circuit the message is retrieved. The proposed scheme has the advantages of being robust against disturbances (internal and external) and being structu rally simple when compared to the existing proposals in the literature, which is important as it leads to cost savings when implemented using analog electronics. To validate the robust ness and simplicity of the proposed scheme, computer simulations using MATLAB/Simulink software were performed