The objective of this paper is to give a comprehensive introduction to applied cryptography with an engineer or computer scientist in mind. The emphasis is on the knowledge needed to create practical systems which supports integrity, confidentiality, or authenticity. Topics covered includes an introduction to the concepts in cryptography, attacks against cryptographic systems, key use and handling, random bit generation, encryption modes, and message authentication codes. Recommendations on algorithms and further reading is given in the end of the paper. This paper should make the reader able to build, understand and evaluate system descriptions and designs based on the cryptographic components described in the paper.

[서평]「Applied Cryptography」

http://romisatriawahono.net/lecture/rm/survey/computer%20vision/Subhedar%20-%20Image%20Steganography%20-%202014.pdf

Current status and key issues in image steganography

In this paper, an algorithm for multiple watermarking based on discrete wavelet transforms (DWT), discrete cosine transform (DCT) and singular value decomposition (SVD) has been proposed for healthcare applications. For identity authentication purpose, the proposed method uses three watermarks in the form of medical Lump image watermark, the doctor signature/identification code and diagnostic information of the patient as the text watermarks. In order to improve the robustness performance of the image watermark, Back Propagation Neural Network (BPNN) is applied to the extracted image watermark to reduce the noise effects on the watermarked image. The security of the image watermark is also enhanced by using Arnold transform before embedding into the cover. Further, the symptom and signature text watermarks are also encoded by lossless arithmetic compression technique and Hamming error correction code respectively. The compressed and encoded text watermark is then embedded into the cover image. Experimental results are obtained by varying the gain factor, different sizes of text watermarks and the different cover image modalities. The results are provided to illustrate that the proposed method is able to withstand a different of signal processing attacks and has been found to be giving excellent performance for robustness, imperceptibility, capacity and security simultaneously. The robustness performance of the method is also compared with other reported techniques. Finally, the visual quality of the watermarked image is evaluated by the subjective method also. This shows that the visual quality of the watermarked images is acceptable for diagnosis at different gain factors. Therefore the proposed method may find potential application in prevention of patient identity theft in healthcare applications.

A proposed secure multiple watermarking technique based on DWT, DCT and SVD for application in medicine

Improved PVO-based reversible data hiding

Steganography is knowledge and art of hiding secret data into information which is largely used in information security systems. Various methods have been proposed in the literature which most of them are not capable of both preventing visual degradation and providing a large embedding capacity. In this paper, we propose a tunable visual image quality and data lossless method in spatial domain based on a genetic algorithm (GA). The main idea of the proposed technique is modeling the steganography problem as a search and optimization problem. Experimental results, in comparison with other currently popular steganography techniques, demonstrate that the proposed algorithm not only achieves high embedding capacity but also enhances the PSNR of the stego image.

A novel image steganography scheme with high embedding capacity and tunable visual image quality based on a genetic algorithm

Data hiding is a well-known technique which embeds the secret data into a digital media. Most of the existing schemes either have the low image quality, or provide the restricted embedding capacity. In this paper, a new data hiding scheme based on turtle shell is proposed to obtain better image quality and higher embedding capacity. In the proposed scheme, a secret digit is embedded into each cover pixel pair with the guidance of the turtle shell. Experimental results reveal that the proposed scheme ensures not only higher embedding capacity, but also obtains better visual quality compared with the existing schemes.

A Novel Turtle Shell Based Scheme for Data Hiding

A high payload steganographic algorithm based on edge detection

Reversible data hiding for high quality images exploiting interpolation and direction order mechanism

Image authentication technique protects the integrity of images Many image authentication schemes have been proposed in recent years However, in these schemes, the image is permanently distorted and cannot be recovered to its original version after image authentication In this paper, we propose a new, reversible watermarking scheme for image authentication scheme in the DWT domain to achieve high accuracy of tamper detection, and complete reversibility while maintaining high image quality of watermarked images In the proposed scheme, authentication code is randomly generated and embedded into 2nd DWT low-frequency subbands of each image block Our experimental results demonstrated that the proposed scheme has ability to resist against different attacks, ie, different sizes of tampered regions, content tampered attack, and collage attack, with small distortion of the watermarked image In addition, the proposed scheme achieves reversibility that is quite important to some special fields, ie, medical images, military images, and fine artwork

A reversible image authentication scheme based on fragile watermarking in discrete wavelet transform domain

Data hiding is a technique for sending secret information under the cover of the digital media. It is usually used to protect privacy and sensitive information when such information is transmitted via a public network. To date, high capacity remains one of the most important research aspects of data hiding. In this study, a new, turtle shell-based data hiding scheme is proposed to improve embedding capacity further while guaranteeing good image quality. In the proposed, turtle shell-based scheme, a reference matrix is composed and a location table is generated. Then, according to the reference matrix and the location table, each pixel pair is processed to conceal four secret bits. The experimental results indicated that the proposed scheme achieved higher embedding capacity and lower distortion of images than some existing schemes.

Thai-Son Nguyen

Papers

A Novel Turtle Shell Based Scheme for Data Hiding

A high payload steganographic algorithm based on edge detection

Reversible data hiding for high quality images exploiting interpolation and direction order mechanism

A reversible image authentication scheme based on fragile watermarking in discrete wavelet transform domain

High capacity turtle shell-based data hiding