Image quality assessment of fast fourier transform domain watermarked images

Digital watermarking is the processing of embedding digital signature into the host media such as image, video, text, audio etc. During the watermarking process, images are subjected to variety of attacks such as noise in transmission channel, geometric attacks,compression, processing like filtering, etc, all this affect the visual quality of watermarked image. Thus, there is a need for image quality assessment of watermarked images in relation to the original images. Several measures of image metrics are available in the field of image processing however they are application based. This paper discusses watermarking in FFT domain and some of the image quality metric that can be applied. Experiments are conducted using the Full Reference (FR) images. We used Mean Square Error (MSE), Root Mean Square (RMS), Structural Similarity (SSIM), Image Fidelity Measure (IFM), Correlation Coefficient Index (CCI) and Peak Signal to Noise Ratio (PSNR) as our quality assessment. Result shows that CCI, SSIM, and IFM are most appropriate for measuring quality of watermarking system

Recent Trends in Communication Networks

In recent years there has been many developments in communication technology. This has greatly enhanced the computing power of small handheld resource-constrained mobile devices. Different generations of communication technology have evolved. This had led to new research for communication of large volumes of data in different transmission media and the design of different communication protocols. Another direction of research concerns the secure and error-free communication between the sender and receiver despite the risk of the presence of an eavesdropper. For the communication requirement of a huge amount of multimedia streaming data, a lot of research has been carried out in the design of proper overlay networks. The book addresses new research techniques that have evolved to handle these challenges

Security protocols suite for machine-to-machine systems

Nowadays, the great diffusion of advanced devices, such as smart-phones, has shown that there is a growing trend to rely on new technologies to generate and/or support progress; the society is clearly ready to trust on next-generation communication systems to face today’s concerns on economic and social fields. The reason for this sociological change is represented by the fact that the technologies have been open to all users, even if the latter do not necessarily have a specific knowledge in this field, and therefore the introduction of new user-friendly applications has now appeared as a business opportunity and a key factor to increase the general cohesion among all citizens. Within the actors of this technological evolution, wireless machine-to-machine (M2M) networks are becoming of great importance. These wireless networks are made up of interconnected low-power devices that are able to provide a great variety of services with little or even no user intervention. Examples of these services can be fleet management, fire detection, utilities consumption (water and energy distribution, etc.) or patients monitoring. However, since any arising technology goes together with its security threats, which have to be faced, further studies are necessary to secure wireless M2M technology. In this context, main threats are those related to attacks to the services availability and to the privacy of both the subscribers’ and the services providers’ data. Taking into account the often limited resources of the M2M devices at the hardware level, ensuring the availability and privacy requirements in the range of M2M applications while minimizing the waste of valuable resources is even more challenging. Based on the above facts, this Ph. D. thesis is aimed at providing efficient security solutions for wireless M2M networks that effectively reduce energy consumption of the network while not affecting the overall security services of the system. With this goal, we first propose a coherent taxonomy of M2M network that allows us to identify which security topics deserve special attention and which entities or specific services are particularly threatened. Second, we define an efficient, secure-data aggregation scheme that is able to increase the network lifetime by optimizing the energy consumption of the devices. Third, we propose a novel physical authenticator or frame checker that minimizes the communication costs in wireless channels and that successfully faces exhaustion attacks. Fourth, we study specific aspects of typical key management schemes to provide a novel protocol which ensures the distribution of secret keys for all the cryptographic methods used in this system. Fifth, we describe the collaboration with the WAVE2M community in order to define a proper frame format actually able to support the necessary security services, including the ones that we have already proposed; WAVE2M was funded to promote the global use of an emerging wireless communication technology for ultra-low and long-range services. And finally sixth, we provide with an accurate analysis of privacy solutions that actually fit M2M-networks services’ requirements. All the analyses along this thesis are corroborated by simulations that confirm significant improvements in terms of efficiency while supporting the necessary security requirements for M2M networks

Research on digital image watermark encryption based on hyperchaos

The digital watermarking technique embeds meaningful information into one or more watermark images hidden in one image, in which it is known as a secret carrier. It is difficult for a hacker to extract or remove any hidden watermark from an image, and especially to crack so called digital watermark. The combination of digital watermarking technique and traditional image encryption technique is able to greatly improve anti-hacking capability, which suggests it is a good method for keeping the integrity of the original image. The research works contained in this thesis include: (1)A literature review the hyperchaotic watermarking technique is relatively more advantageous, and becomes the main subject in this programme. (2)The theoretical foundation of watermarking technologies, including the human visual system (HVS), the colour space transform, discrete wavelet transform (DWT), the main watermark embedding algorithms, and the mainstream methods for improving watermark robustness and for evaluating watermark embedding performance. (3) The devised hyperchaotic scrambling technique it has been applied to colour image watermark that helps to improve the image encryption and anti-cracking capabilities. The experiments in this research prove the robustness and some other advantages of the invented technique. This thesis focuses on combining the chaotic scrambling and wavelet watermark embedding to achieve a hyperchaotic digital watermark to encrypt digital products, with the human visual system (HVS) and other factors taken into account. This research is of significant importance and has industrial application value

Dynamic block encryption with self-authenticating key exchange

One of the greatest challenges facing cryptographers is the mechanism used for key exchange. When secret data is transmitted, the chances are that there may be an attacker who will try to intercept and decrypt the message. Having done so, he/she might just gain advantage over the information obtained, or attempt to tamper with the message, and thus, misguiding the recipient. Both cases are equally fatal and may cause great harm as a consequence. In cryptography, there are two commonly used methods of exchanging secret keys between parties. In the first method, symmetric cryptography, the key is sent in advance, over some secure channel, which only the intended recipient can read. The second method of key sharing is by using a public key exchange method, where each party has a private and public key, a public key is shared and a private key is kept locally. In both cases, keys are exchanged between two parties. In this thesis, we propose a method whereby the risk of exchanging keys is minimised. The key is embedded in the encrypted text using a process that we call `chirp coding', and recovered by the recipient using a process that is based on correlation. The `chirp coding parameters' are exchanged between users by employing a USB flash memory retained by each user. If the keys are compromised they are still not usable because an attacker can only have access to part of the key. Alternatively, the software can be configured to operate in a one time parameter mode, in this mode, the parameters are agreed upon in advance. There is no parameter exchange during file transmission, except, of course, the key embedded in ciphertext. The thesis also introduces a method of encryption which utilises dynamic blocks, where the block size is different for each block. Prime numbers are used to drive two random number generators: a Linear Congruential Generator (LCG) which takes in the seed and initialises the system and a Blum-Blum Shum (BBS) generator which is used to generate random streams to encrypt messages, images or video clips for example. In each case, the key created is text dependent and therefore will change as each message is sent. The scheme presented in this research is composed of five basic modules. The first module is the key generation module, where the key to be generated is message dependent. The second module, encryption module, performs data encryption. The third module, key exchange module, embeds the key into the encrypted text. Once this is done, the message is transmitted and the recipient uses the key extraction module to retrieve the key and finally the decryption module is executed to decrypt the message and authenticate it. In addition, the message may be compressed before encryption and decompressed by the recipient after decryption using standard compression tools

Design And Implementation Of A Secure Uhf Rfid Protocol On Fpga

Tez (Yüksek Lisans) -- İstanbul Teknik Üniversitesi, Fen Bilimleri Enstitüsü, 2013Thesis (M.Sc.) -- İstanbul Technical University, Institute of Science and Technology, 2013Tezin ilk aşamasında, yeni okuyucu ve etiket yapılarının geliştirilmesinin ardından güvenli bir UHF RFID sisteminin FPGA üzerinde tasarımı yapılmış ve gerçeklenmiştir. Haberleşme mesafesini geniş ve güvenlik seviyesini yüksek tutmak amacıyla sistem tasarımında aktif etiket yapısı kullanılmıştır. Avrupa UHF RFID standartları göz önüne alınarak merkez frekansı 868MHz olarak belirlenmiştir. Düşük güç tüketimi ve ayarlanabilir çalışma noktası özelliklerine bağlı olarak Okuyucu ve etiket yapılarının alıcı verici katlarında RFM22B modülleri kullanılmıştır. Işlem kapasitesinin yüksek tutulması amacıyla mikroişlemci katında FPGA kitleri kullanılmıştır. Haberleşme protokolünde 2 yönlü doğrulama yapan bir protokol tercih edilmiştir. Iletilen verinin sifrelenmesi Tiny Encryption Algorithm ile gerçekleştirilmiştir. Sonuç olarak 64 bit veri ile kimlik doğrulama işlemi gerçekleştiren bir RFID sistemi başarıyla gerçeklenmiştir. Tezin ikinci aşamasında okuyucuya karşı yeniden oynatma atakları yapılmıştır. Bu ataklar ile asıl etiketin yerine geçilerek okuyucunun gerçek etiket ile haberleştiğine inandırılması amaçlanmıştır. Bu amaçla, daha önceden tasarlanan okuyucu ve etiket yapılarına benzer bir atak birimi tasarlanmış ve öncelikli olarak okuyucu-etiket arasındaki haberleşme 1000 defa dinlenmiştir. Dinleme sonucu elde edilen verilen bilgisayar ortamında saklanmıştır. Sonrasında, asıl etiketin aktif olmadığı durumda, atak birimi okuyucudan gelen veriyi daha önceden kaydedilen veriyle karşılaştırmış ve eşleşme olduğu takdirde bahsedilen okuyucu verisine cevap olan etiket verisini okuyucuya geri göndermiştir. Sonuç olarak tasarlanan RFID sisteminin yeniden oynatma ataklarına karşı güvenilirliği arttırılmıştır.Design and implementation of a secure UHF RFID system was accomplished in first phase of the thesis, by proposing new reader and transponder hardware. Active tag architecture was preferred in system design to keep the communication range long and security level high. 868 MHz center frequency is selected for system operation considering European UHF band RFID regulations defined by European Telecommunication Standards Institute (ETSI). RFM22B transceiver modules were decided on and used for RF front-end stages of reader and tag taking into low power consumption and flexible operating features. FPGA boards formed up microcontroller part of designed reader and tag to keep the computational power substantially high. A communication protocol with two way authentication mechanism was used between receiver and transmitter devices. Tiny Encryption Algorithm was preferred in the design to secure the transmitted data. As a result, a secure RFID system with 64 byte authentication procedure was implemented. In second part, attack studies were held on designed system. The aim of the attacks were to impersonate the original tag with an attack device and convince the reader that original tag is in range of communication. To accomplish replay attacks, an attack device similar to the reader and tag architecture, was designed and prepared for operation. Firstly, reader and tag data was listened by attack device and sent to a personal computer for storage over serial communication link. Later on, stored data is replayed back to the reader when the original tag was out of communication range.Yüksek LisansM.Sc

Digital watermarking methods for data security and authentication

Philosophiae Doctor - PhDCryptology is the study of systems that typically originate from a consideration of the ideal circumstances under which secure information exchange is to take place. It involves the study of cryptographic and other processes that might be introduced for breaking the output of such systems - cryptanalysis. This includes the introduction of formal mathematical methods for the design of a cryptosystem and for estimating its theoretical level of securit

Uticaj fedinga na komunikaciju senzorskih čvorova u bežičnim nosivim telesnim senzorskim mrežama za vojnu primenu

Svakodnevno se uvećavaju zahtevi za informacijama u procesu odlučivanja. Savremena bojišta svakako nisu izuzetak, jer se na osnovu tačnih i pravovremenih informacija mogu donositi odluke koje na kraju mogu spasiti ljudske živote, smanjiti upotrebu prekomerne sile ili pak uništenje vojne tehnike. Količine i vrste podataka koje senzorske mreže generišu na samom terenu postavljaju tehničke izazove pred komunikacionu tehniku da obezbede pravilan, potpun i bezbedan način protoka informacija. Jedan od problema koji je potrebno istražiti je komunikacija bežičnih senzorskih mreža koje imaju nove karakteristike i zahteve na komunikacionim sistemima i mrežnim protokolima, a koji se razlikuju od konvencionalnih mreža za komunikaciju podataka. Pojava fedinga u bežičnim senzorskim mrežama je sigurna, ali sam sistem svojom konfiguracijom senzorskih čvorova i kombinacijom bežičnih tehnologija čini da se interferencija u kanalu smanji i poveća kapacitet protoka samog kanala. Bežične senzorske mreže se organizuju u hijerarhiskom i ćelijskom nivou. S druge strane veliki broj ćelija utiče da se poveća i broj radio kanala, a sa povećanjem broja radio kanala dolazi do međukanalne interferencije što direktno utiče kvalitet prenosa podataka radio kanalom. Cilj je postići potreban nivo kapaciteta u prenosu i kvaliteta u prijemu signal na krajnoj tački. Dodatak, konvencionalnim RF sistemima komunikacije, u obliku FSO komunikacionih sistema predstavljaju značajno unapređenje koje može unaprediti performanse, brzine prenosa i bezbedniji prenos podataka. U radu je predložena hibridna RF/FSO mobilna senzorska mreža koja uspešno treba za prevaziđe komunikacione probleme konvencionalne RF mreže. U radu je istražena mogućnost da se kroz optički kanal u prisustva fedinga (scintilacije) prenesu kompleksniji podaci (slika, video i sl.), kao i kako u prisustvu fedinga u optičkom kanalu dolazi do degradacije podatka

Fractional Calculus and the Future of Science

Newton foresaw the limitations of geometry’s description of planetary behavior and developed fluxions (differentials) as the new language for celestial mechanics and as the way to implement his laws of mechanics. Two hundred years later Mandelbrot introduced the notion of fractals into the scientific lexicon of geometry, dynamics, and statistics and in so doing suggested ways to see beyond the limitations of Newton’s laws. Mandelbrot’s mathematical essays suggest how fractals may lead to the understanding of turbulence, viscoelasticity, and ultimately to end of dominance of the Newton’s macroscopic world view.Fractional Calculus and the Future of Science examines the nexus of these two game-changing contributions to our scientific understanding of the world. It addresses how non-integer differential equations replace Newton’s laws to describe the many guises of complexity, most of which lay beyond Newton’s experience, and many had even eluded Mandelbrot’s powerful intuition. The book’s authors look behind the mathematics and examine what must be true about a phenomenon’s behavior to justify the replacement of an integer-order with a noninteger-order (fractional) derivative. This window into the future of specific science disciplines using the fractional calculus lens suggests how what is seen entails a difference in scientific thinking and understanding