F5 Steganography Research Articles

Stego key recovery method for F5 steganography with matrix encoding

When embedding secret message into image by steganography with matrix encoding, there are still no effective methods to recover the stego key because it is difficult to statistically distinguish the stego coefficient sequences selected by true and false keys. Therefore, this paper proposes a method for recovering the stego key of a typical JPEG (Joint Photographic Experts Group) image steganography—F5 which composes of the check matrix and shuffling key. Firstly, the check matrix is recovered based on the embedding ratio estimated by quantitative steganalysis. The shuffling key is then recovered based on the distribution difference between the bit sequences extracted by the true and false shuffling keys. Additionally, the cardinality of the shuffling key space is significantly reduced by examining the extracted encoding parameter and message length. Experimental results show that the proposed method can recover the stego key accurately and efficiently, even when the existing Xu’s method fails for the high or very low embedding ratio.

Payload location for JPEG image steganography based on co-frequency sub-image filtering

In digital steganography, due to difficulties estimating the JPEG cover image, it is still very hard to accurately locate the hidden message embedded in a JPEG image. Therefore, this study proposes a payload location method for a category of pseudo-random scrambled JPEG image steganography. In order to estimate the quantized discrete cosine transform coefficients in the cover JPEG image, a cover JPEG image estimation method is proposed based on co-frequency sub-image filtering. The proposed payload location method defines a general residual, uses the estimated cover JPEG image to compute the residuals, and then employs the mean residuals of multiple stego images embedded along the same path to distinguish the stego positions. The proposed cover JPEG image estimation method constructs 64 co-frequency sub-images, and then filters the sub-image to estimate the cover JPEG image. Finally, using these methods, payload location algorithms are designed for two common JPEG image steganography algorithms: JSteg and F5. Experimental results show that the proposed location algorithms can effectively locate the stego positions in both JSteg and F5 steganography when the investigator possesses multiple stego images embedded along the same path. In addition, the location results can also be used to recover the steganography key to extract the embedded secret messages.

Stego key recovery based on the optimal hypothesis test

At present, research on steganalysis is mainly focused on the existence detection of hidden messages. However, the extraction of hidden messages, i.e., extraction attacks, also plays a decisive role in tasks such as obtaining evidence of covert communication and fighting against criminal activities. For steganography using a stego key, the purpose of an extraction attack is to recover the stego key. This paper mainly studies methods of recovering the stego key for least significant bit (LSB) steganography in the JPEG domain. Firstly, based on the differences in the statistical properties of the discrete cosine transform (DCT) coefficients between the paths generated by the correct and incorrect keys, a stego key recovery model based on the optimal hypothesis test is proposed. Moreover, formulas are given for calculating the desired sample size and threshold in the proposed stego key recovery model. Secondly, based on the difference in the distributions of odd and even coefficients between the correct and incorrect paths, a method of recovering the stego key for OutGuess steganography using this model is proposed. Finally, based on the difference in the distributions of zero and non-zero coefficients between the correct and incorrect paths, a method of recovering the stego key for F5 steganography (modified version) using this model is proposed. Experimental results for OutGuess 0.13b, OutGuess 0.2 and modified F5 steganography show that the proposed method can successfully recover the stego key and that its performance is superior to that of existing methods.

Perbandingan Kapasitas Pesan pada Steganografi DCT Sekuensial dan Steganografi DCT F5 dengan Penerapan Point Operation Image Enhancement

Steganographic process on the DCT transform is generally done on the value of DCT quantization process results that have a value other than 0, this relates to the distribution of the diversity of pixels in the image. Applying point operation of image enhancement (POIE) in the form of histogram equalization, contrast stretching, brigthening and gamma correction on the image of the reservoir is associated with the image histogram . Test parameters used is the number of bits that can be accommodated message, PSNR and MSE value, and the value of DCT coefficients quantization results. Based on test results that have to be got several conclusions that capacity steganographic message on DCT sequential greater than the DCT F5 steganography either before or after application of the application POIE, stego image quality on DCT steganography F5 better than the sequential DCT steganography well before the application POIE and after application of POIE, both F5 and steganography steganography DCT DCT sequential equally resistant to manipulation of stego image.

A Survey Paper on Steganalysis F5 Algorithm

Steganography is a technique which used for securing the secret information from the illegal activity. Steganalysis is technique of finding the hidden text from the stego image. A Steganalysis based on the DCT value of the image is proposed in this paper. Steganography F5 algorithm is greater secure than other algorithm. In this paper survey on Steganalysis algorithm for attacking on F5 steganography algorithm is presented. When embedding rate is decreased from 10% to 5% then its accuracy is decreased that needs to improve and also need to decrease the processing time for that algorithm. Proposed techniques also discussed in this paper.

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.

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.

On F5 Steganography in Images

Steganalysis is the reasonable method to detect whether the transmitted media content contains secret messages (e.g. business secrecy). This paper proposes two steganalysis methods to estimate the modification ratio of F5 steganography and its improved version that are popularly used to hide secrecy in images. The proposed methods measure the distance between the coefficient histogram of a given image and that of an estimated stego image. The distance is measured based on relative entropy that has the superiority of measuring the distance between two distributions. The estimated modification ratio can be used to distinguish the stego images marked by F5 steganography or its improved version from the original images. Experimental results are given to show that the proposed methods outperform the existing quantitative steganalysis methods against F5 steganography and its improved version.