Visual Attacks Research Articles

A steganographic method via various animations in PowerPoint files

In a PowerPoint file, animation effects are used to emphasize objects, timing effects are used to control the presentation time, and slide transition effects are used to highlight particular slides. Thus, using various effects can make the presentation of a PowerPoint file more colorful and attractive. In this paper, we propose a steganographic method to embed message in a PowerPoint file via various effects. In contrast to other steganographic methods, we not only hide message naturally but also keep the content of the cover media intact. Furthermore, the proposed method can resist the format conversion attack. The experiment result demonstrates that the proposed method is undetectable under some visual and statistical attacks.

STEGNOGRAPHY OF HIGH EMBEDDING EFFICIENCY BY USING AN EXTENDED MATRIX ENCODING ALGORITHM

F5 Steganography is way totally different from most of LSB replacement or matching steganographic schemes, as a result of matrix encryption is used to extend embedding potency while reducing the amount of necessary changes. By victimisation this theme, the hidden message inserted into carrier media observably is transferred via a safer imperceptible channel. The embedding domain is that the quantitative DCT coefficients of JPEG image, which makes the theme, be proof against visual attack and statistical attack from the steganalyst. Based on this effective theme, An extended matrix encoding algorithm is planned to improve the performance further in this paper. The embedding potency and embedding rate get accrued to large extent by changing the hash function in matrix encryption and changing the coding mode. Eventually, the experimental results demonstrate the extended algorithm is more advanced and efficient to the classic F5 Steganography.

A 3-Level Secure Histogram Based Image Steganography Technique

Steganography is an art that involves communication of secret data in an appropriate carrier, eg. images, audio, video, etc. with a goal to hide the very existence of embedded data so as not to arouse an eavesdropper's suspicion. In this paper, a steganographic technique with high level of security and having a data hiding capacity close to 20% of cover image data has been developed. An adaptive and matched bit replacement method is used based on the sensitivity of Human Visual System (HVS) at different intensities. The proposed algorithm ensures that the generated stego image has a PSNR greater than 38.5 and is also resistant to visual attack. A three level security is infused into the algorithm which makes data retrieval from the stego image possible only in case of having all the right keys.

Uncompressed Image Steganography using BPCS: Survey and Analysis

Steganography is the art and science of hide secret information in some carrier data without leaving any apparent evidence of data alternation. In the past, people use hidden tattoos, invisible ink or punching on papers to convey stenographic data. Now, information is first hide in digital image, text, video and audio. This paper discusses existing BPCS (Bit Plane Complexity Segmentation) steganography techniques and presences of some modification. BPCS technique makes use of the characteristics of the human visible system. BPCS scheme allows for large capacity of embedded secret data and is highly customized. This algorithm offers higher hiding capacity due to that it exploits the variance of complex regions in each bit plane. In contrast, the BPCS algorithm provided a much more effective method for obtaining a 50% capacity since visual attacks did not suffice for detection. Keywords: BPCS, Data security, Information hiding, Steganography, Stego image

Hybrid and Blind Steganographic Method for Digital Images Based on DWT and Chaotic Map

Steganography is the art and science of hiding secret information into digital media with the intention to transmit this information. Most of the steganographic methods either use spatial domain or frequency domain for embedding the secret information. Current hybrid methods require the original cover image to extract the secret information making these methods to become not practical. This paper proposes a new blind steganographic method for digital images that combines spatial and frequency domains and does not rely on the cover image in extracting the secret information. The proposed method utilizes a chaotic map to scramble the secret information before the embedding procedure takes place. A coding map is generated during the work on spatial domain, and the original image is transformed into DWT domain, then the generated coding map is embedded in the coefficients of LL and HL sub-bands of the cover image. The drawn experimental results show that the resultant stego-images have high quality and the proposed method provides high embedding capacity compared with other methods and is robust against the visual analysis and other image processing attacks such as lossy compression and added noise. 

New steganography algorithm to conceal a large amount of secret message using hybrid adaptive neural networks with modified adaptive genetic algorithm

In this paper, we propose a new steganography algorithm using non-uniform adaptive image segmentation (NUAIS) with an intelligent computing technique to conceal efficiently a large amount of confidential messages (Smsg) into color images. Whereas, the number of secret bits to be replaced is non uniform from byte to another byte; it based on byte characteristics, which are extracted by using 16 byte levels (BL) with variance distribution of the Neighboring Eight Bytes (NEB) around the current byte. Four security layers are introduced to increase resistance against statistical and visual attacks. These layers are designed to make an excellent imperceptible concealing Smsg with lower distortion of a color plane and high protection of Smsg. The proposed intelligent technique using the hybrid adaptive neural networks and modified adaptive genetic algorithm employing uniform adaptive relaxation (ANN_AGAUAR) is working as the fourth security layer to improve the quality of the stego image (Is). The results are discussed and compared with the previous steganography algorithms; it demonstrates that the proposed algorithm's effectiveness can be concealed efficiently the number of secret bits reached to four bits per byte with better visual quality.

Message Segmentation to Enhance the Security of LSB Image Steganography

Classic Least Significant Bit (LSB) steganography technique is the most used technique to hide secret information in the least significant bit of the pixels in the stego-image. This paper proposed a technique by splitting the secret message into set of segments, that have same length (number of characters), and find the best LSBs of pixels in the stego-image that are matched to each segment. The main goal of this technique is to minimize the number of LSBs that are changed when substituting them with the bits of characters in the secret message. This will lead to decrease the distortion (noise) that is occurred in the pixels of the stego-image and as result increase the immunity of the stego-image against the visual attack. The experiment shows that the proposed technique gives good enhancement to the Classic Least Significant Bit (LSB) technique.

A New Image Steganography Based on Decimal-Digits Representation

Steganography is the art and science of hiding important information by embedding message within other file. In this paper, a new technique to hide text message in image by using what is called image steganography. By representing the ASCII code decimal value of each character, in the secret message, as a set of separated single decimal-digit, also represent each decimal pixel value in the stego-image as a set of separated single decimal-digit. The technique creates a matching list between the decimal-digits of the characters in the secret message with the decimal-digits of the pixels in the stego-image. The technique compresses the created matching list to be as small as possible to embed it in the unused file space at the end of the stego-image file. The results show that our technique provides more security against visual attack because it does not make any changes in the pixel of the stego-image.

An extended matrix encoding algorithm for steganography of high embedding efficiency

F5 steganography is much different from most of LSB replacement or matching steganographic schemes, because matrix encoding is employed to increase embedding efficiency while reducing the number of necessary changes. By using this scheme, the hidden message inserted into carrier media imperceptibly can be transferred via a more secure subliminal channel. The embedding domain is the quantized DCT coefficients of JPEG image, which makes the scheme be immune to visual attack and statistical attack from the steganalyst. Based on this effective scheme, an extended matrix encoding algorithm is proposed to improve the performance further in this paper. By changing the hash function in matrix encoding and converting the coding mode, the embedding efficiency and embedding rate get increased to a large extent. Eventually, the experimental results demonstrate the extended algorithm is superior to the classic F5 steganography.

Steganalysis Of The Image By Visual and Statistical Attacks

Steganalysis Of The Image By Visual and Statistical Attacks

Alleviation of Brain Hypoperfusion after Preventative Treatment with Lomerizine in an Elderly Migraineur with Aura

Previous studies of brain single-photon emission tomography (SPECT) showed changes of regional cerebral blood flow (rCBF) in migraineurs during prodromes or headache attacks. Little is known about how successful medication of migraine prevention can reflect rCBF in migraineurs. We highlighted alternation of brain SPECT findings in a migraineur with aura before and after prophylactic treatment with lomerizine, a calcium channel blocker. A 70-year-old man with migraine developed visual disturbance frequently at walking exercise for the recent 3 months. After this visual attack, a mild-degree of throbbing headache occured occasionally. Brain SPECT using 99mTc-ethyl cysteinate dimer was performed at interictal time of migraine. Brain SPECT before lomerizine treatment revealed hypoperfusion in the frontal, parietal, and occipital regions. He was diagnosed with recurrence of migraine with aura (MA). Lomerizine (10 mg/day, po) was administered for 3 months. MA and visual aura without headache were dramatically improved. Migraine attacks and visual disturbance were not induced at exercise. At 3 months after lomerizine medication, brain SPECT showed remarkable increase of rCBF. These SPECT changes of our patient indicated that antimigraine mechanism of lomerizine could contribute to restoration of cerebral hypoperfusion.

This scream I've thrown out is a dream: corporeal transformation through sound, an Artaudian experiment

Antonin Artaud's last radio recording from 1948 is one of his final projects of corporeal transformation: where the visual body is completely absent in radio broadcasting, Artaud's body without organs puts together words, music, screams, glossolalia and laughter as visual attacks where sound is recognized as the real mark of the body. Even if the recordings were not broadcast by the radio station, they are a rare experiment to actively end the process of representation through sound. The scream becomes the means to transmit the body without organs by destroying meaning and representation.

Steganography in Colored Images Using Information Reflector with 2^k Correction

Steganography is a process that involves hiding a message in an appropriate carrier for example an image or an audio file. The carrier can then be sent to a receiver without anyone else knowing that it contains a hidden message. The aim of this study was to investigate the various steganograhy methods & how they are implemented .LSB is a very well known method in this field. In binary images we are very much restricted in the scope as there are only 4 bits or 8 bits to represent a pixel so we are very much restricted to most popular LSB methods .But in colored images there are generally up to 24 bits images with three different RGB channels, if using RGB color space .So, we can explore a lot many new methods which can manipulate or use various channels of colored images in regular or arbitrary pattern to hide the information. Using this concept we have explored the various existing methods of data hiding in colored images & taken an intersection between the arbitrary pixel manipulation & LSB method to propose our work which uses arbitrary channel of a pixel to reflect the presence of data in one or two other channels. Finally we have used the 2k correction method to improve the stego image so as to assure the maximum security against the visual attacks. We have proved that this work shows an attractive result as compared to the other present algorithms on the various parameters like security, imperceptibility capacity & robustness.At the end the new steganography technique is also compared with the available techniques.

Imperceptible Watermarking Scheme for Fundus Images Using Intra-Plane Difference Expanding

This paper proposes an imperceptible watermarking scheme for digital fundus images. It is a pooled approach of two schemes proposed in (1) and (2). Hiding a large amount of data (image, audio, text) file into color BMP images proposed in (1).It could achieve the better capacity in irreversible way which is not suitable for fundus images. The difference expanding method proposed for medical images in (2). It suffered from imperceptibility. Hence, these two schemes were combined in the proposed scheme by addressing better capacity, imperceptibility, reversibility and robustness. The embedding process in the proposed scheme involves two steps. First step selects the pixel according to the color characteristics of the fundus images. Second step embeds the secret information into selected pixels by using the difference expanding method of the two pixels from different color planes. It is known as intra-plane difference expanding. It embeds more than one bit at each byte in one pixel of the fundus image and give us imperceptible results. This scheme is robust to statistical and visual attacks. The comparison results showed the improvement of imperceptivity to 15% in the proposed scheme with respect to the scheme proposed in (1). It also identified that that 30000 bits is the optimum size of the watermark with good level of imperceptibility which is above 60 dB at an average.

A Novel Technique for Image Authentication in Frequency Domain Using Discrete Fourier Transformation Technique (IAFDDFTT)

In this paper a novel technique for Image Authentication in Frequency Domain using Discrete Fourier Transformation Technique (IAFDDFTT) has been proposed to authenticate a gray level PGM, TIFF image by embedding a message/image where 2 x 2 submatrix is taken as source matrix from the image matrix and transform into the frequency domain. Two bits of authenticating message/image are fabricated within the real part of each pixel, excluding the first pixel of each submatrix where the position is chosen using a hash function. The process is repeated for each submatrix on row major order to insert authenticating message/image content and 128 bits Message Digest (MD-5), generated from authenticating message/image. Inverse DFT is performed to transform the embedded image from frequency to spatial domain as final step of encoding. The decoding is done through the reverse procedure. The experimental results against statistical and visual attack has been discussed and compared with the existing steganography algorithm like S-Tools. Histogram analysis, noise analysis, and standard deviation computation of source image with embedded image shows the better results in comparison with existing S-Tools.

Hiding a Large Amount of Data with High Security Using Steganography Algorithm

This study deals with constructing and implementing new algorithm based on hiding a large amount of data (image, audio, text) file into color BMP image. We have been used adaptive image filtering and adaptive image segmentation with bits replacement on the appropriate pixels. These pixels are selected randomly rather than sequentially by using new concept defined by main cases with their sub cases for each byte in one pixel. This concept based on both visual and statistical. According to the steps of design, we have been concluded 16 main cases with their sub cases that cover all aspects of the input data into color bitmap image. High security layers have been proposed through three layers to make it difficult to break through the encryption of the input data and confuse steganalysis too. Our results against statistical and visual attacks are discussed and make comparison with the previous Steganography algorithms like S-Tools. We show that our algorithm can embed efficiently a large amount of data that has been reached to 75% of the image size with high quality of the output.

Visual Phenotype of Multiple Sclerosis in the Afro-Caribbean Population and the Influence of Migration to Metropolitan France

To describe the visual phenotype of multiple sclerosis (MS) in the Afro-Caribbean population living in Martinique (French West Indies) and to specify the influence of the migration to metropolitan France on ocular impairment. Prospective consecutive observational case series. A complete ophthalmologic examination was performed. A total of 112 patients of Afro-Caribbean origin with MS satisfying McDonald's diagnostic criteria, divided into 53 cases (47.3%), the non-migrant patients (group NM), who had never left the Caribbean basin, and 59 cases (52.7%), the migrant patients (group M), who had lived in metropolitan France for at least 1 year before age 15. MS first manifested as an impairment of the optic nerve in 41 cases (36.6%): 25 cases (47.1%) in group NM and 16 cases (27.1%) in group M. Visual function was recovered in 13/25 cases (52%) in group NM compared to 13/16 cases (81%) in group M. Two-thirds of patients presented with a clinical ocular impairment, which was bilateral in 58.5% of cases in group NM. Fourteen cases (12.5%) met the criteria of neuromyelitis optica, nine cases (17%) in group NM and five cases (8.5%) in group M. In group NM, when the initial visual attack did not regress, the visual Expanded Disability Status Scale (EDSS) score was 5+/-1.5 ; 75% of patients had monocular blindness and 50% binocular. In the non-migrants (group NM), MS manifested more frequently with an optical neuropathy, the ocular impairment was more severe, and corresponded to neuromyelitis optica in 17% of the cases; a visual presentation and the absence of complete recovery from the first attack represented a factor of poor prognosis. This series is the largest description of the visual phenotype of MS in patients of African origin. The results confirm the preferential impairment of the optic nerve in the black population in the course of the disease. The migration towards an area of high prevalence of MS influences the visual phenotype in terms of a lower incidence and less severe prognosis of ocular impairment.

Investigating Steganographic Communications

In this paper we present different approaches to steganography investigation with focus on digital images. We look at steganography tools along with their specific signatures. We present experimental results regarding visual and statistical attacks for steganography detection. We report about emerging directions in this area of research and tips for monitoring steganographic communications.

Nomadic Savages, Ochre People and Heroic Herders: Visual Presentations of the Himba of Namibia's Kaokoland

The pastoral Himba of Namibia's semiarid northwest have been objects of colonizing and globalizing cameras over the last century. They have been presented as isolated, subsistence-oriented herders, savage beauties, polygamous patriarchs, and persistent desert dwellers. Timelessness and marginality have been salient topics of the visual presentations of herders in Namibia's semiarid northwest. Today, Namibia's discourse on "the indigenous" is frequently pictured with images of the Himba. Especially Himba women were made the focus of the media gaze. Visual images of Himba women seemingly fill the need for esthetic presentation and offer a platform for imaginations and desires. This article seeks to describe how and why the Himba, and Himba women especially, became icons of a romanticized and estheticized Africa within a global discourse. After discussing early maps and early colonial photography, the heydays of the "Colonizing Camera" are outlined. The colonial "visual attack" was three-pronged: colonial officials seeking assertion for their ideas of indirect rule and of white supremacy, the settler elite looking for pleasure in an undisturbed natural world and frequently conflating nature and people in their photographic presentations, and finally scientists seeking for answers to various "scientific enigmas" and ethnographic descriptions before an "ancient culture" would finally fade away. Finally, visual representations after 1990--Namibia's year of Independence--are analyzed. Three visual themes are dominating discourses at the turn of the millennium: the endangered indigenous world, the esthetic and erotic appeal of indigenous women, and the many attractions of cultural tourism targeting an authentic indigenous lifestyle.

Performance of Portland limestone cements in mortar prisms immersed in sulfate solutions at 5 °C

The results of a test programme to investigate the sulfate resistance of mortars, immersed up to 12 months at 5 °C in magnesium sulfate and sodium sulfate solutions, is described. The mortars were prepared from four cements; a Portland cement, a sulfate-resisting Portland cement and two Portland limestone cements containing 15% by mass of an oolitic limestone and a carboniferous limestone. The mortar specimens were subject to BS 5328 Class 4A and 4B sulfate exposure conditions. These are the highest classes for concretes prepared using sulfate-resisting Portland cement (SRPC) before surface protection is required and are two and three classes higher than those recommended for concretes prepared using Portland cement (PC) and Portland limestone cement (PLC), respectively. Two free water-cement ratios were used, 0.5 and 0.75. Performance was monitored by visual assessment, expansion and changes in flexural and compressive strengths. At a free water-cement ratio of 0.75, the PC mortars and PLC mortars exhibited visually very severe attack with the former showing expansion and reductions in strength, and the latter mainly reductions in strength. At a free water-cement ratio of 0.50 both the PC mortars and PLC mortars showed slight/moderate to severe visual attack, the degree of deterioration appearing slightly greater in the PLC mortars, more especially those made with oolitic limestone. The PLC mortars also exhibited reductions in compressive failure load. The SRPC mortars exhibited little visual deterioration, no expansion, a small increase in flexural strength and no significant reductions in compressive strength. At a free water-cement ratio of 0.75 substantial amounts of thaumasite, together with ettringite was present in the surface layers of the deteriorated PLC mortars whilst ettringite was present in the surface layers of the deteriorated PC mortars. It is concluded that mortars made with a PC with a C 3A content of about 10% by mass were broadly similar in their vulnerability to sulfate attack at 5 °C as PLC mortars containing 15% limestone by mass, although the mode of attack was different.