This paper proposes an innovative method that aligns a polyphonic audio recording of music to its corresponding symbolic score. In the first step, we perform onset detection and then apply constant Q transform around each onset. A similarity matrix is computed by using a scoring function which evaluates the similarity between notes in the music score and onsets in the audio recording. At last, we use dynamic programming to extract the best alignment path in the similarity matrix. We compared two onset detectors and two note matching methods. Our method is more efficient and has higher precision than the traditional chroma-based DTW method. Our algorithm achieved the best precision, which are 10% higher than the compared traditional algorithm when the tolerance window is 50 ms.

Abstract The vast potential of information and communication technologies such as computer‐based communication networks and telecommunication systems is indeed blooming innovations. This paper is a novel attempt in the field of authorization and access control, which uses steganography that coverts the data into a form that cannot be interpreted by unauthorized persons. The proposed algorithm transfers compressed data and hides it into a cover medium by improvising existing run‐length technique in steganography. It deals with a compression technique that uses the redundancy feature of a bitstream and then uses this compressed stream to embed data in an image. The run‐length encoding technique is exploited to compress a bitstream being embedded in a cover image. However, run‐length encoding method has inefficient compression like the sharp bitstreams, such as the pattern “101010101”. This study developed a novel high‐capacity steganographic access control in data hiding to transform sharp bitstreams into smooth bitstreams before it is hidden into a cover image. Our scheme performs the logical Exclusive‐OR (XOR) operation to smoothen the secret bitstream and to embed the result into a cover medium. Additionally, the proposed scheme employs generalized difference expansion transform for image recovery after data extraction; consequently, the image fidelity can be preserved. The experimental results show that our scheme owns a higher embedding capacity than previous approaches while maintaining high image quality. Copyright © 2011 John Wiley & Sons, Ltd.

Abstract With the purpose of accessing numerous network resources and services with user anonymity, various dynamic identity (ID)‐based user authentication schemes have been proposed. Recently, Khanet al. have pointed out the security weaknesses of the dynamic ID‐based user authentication scheme of Wanget al. and proposed an improved version of dynamic ID‐based user authentication scheme for remote login systems. They claimed that their scheme can withstand various security attacks and provide user anonymity. However, we found that the scheme of Khanet al. cannot preserve user anonymity if login message and system parameters are collected by the attacker. To ensure user anonymity, in this paper, we propose a new dynamic ID‐based user authentication scheme for remote login environments and the proposed scheme enables the user's real identity to mask periodically when the user logs into the remote server. Compared with the related schemes, the proposed scheme satisfies more admired criteria and it is suitable even for applications in low‐power computing environments. Finally, we formally prove the security of the proposed scheme by employing the Burrows–Abadi–Needham logic. Copyright © 2015 John Wiley & Sons, Ltd.

Multimedia hiding system is to embed message behind the specified media, but it is still kept normal in media representations via human sensitive organizations without causing imperceptibility. In this article, we propose a data hiding system by means of flexible exploiting modification directions to achieve safer message concealments in image-media. In our scheme, n cover-pixels are flexibly chosen on modulo operations to embed a secret s , where n = ⌈ log 3 ( s ) ⌉. The varied pixel values associated with the chosen n pixels are only changed among [-1, 1]. Because the numbers of adjustable pixels are much greater than the pixels in the past scheme, our scheme is able to obtain a higher embedded ratio in response to the capacity requirements of information hiding systems. In addition, we also applied the statistics-steganalyzers to demonstrate that our scheme has accomplishment not only higher capacity but also kept the robustness against the blind steganalyzers.

E-forensics investigates and extracts confidential information from electronic products; in other words, the anti-forensics indicates that evidences in those products are imperceptible and undetected. This work presents an anti-forensic steganography method that can embed and extract messages from images. Highlight of exploiting modification direction (HoEMD) and adaptive EMD (AdEMD) methods use the module operation and take into account of the sensitive nature of a human visual system. The HoEMD approach exploits the pixel directions. A pixel with a larger change implies more pixel directions and, ultimately, a larger embedding capacity. The pixel differencing in the proposed AdEMD method is used to evaluate whether the pixel located in the edge area can tolerate a larger change than that of the pixel location in a smooth area. To successfully extract a message, the differencing value is maintained on the same level before and after data is concealed; a delicate adjusting phase is used as well. In contrast with the PVD and LSB replacement method of Wu et al., LSB substitution method, and Lee and Chen's data hiding scheme based on modulus function, the proposed steganography system has a larger embedding capacity and a higher image quality. Effectiveness of the proposed steganography schemes over that of a previous blind steganalyzer is demonstrated using the statistical attack of Chi-square analysis.

In order to provide large embedding capacity and to minimize distortion for the stego-image, a steganographic method using multi-pixel differencing is presented in this paper. It takes into consideration four pixels of a block, and the differences between the lowest gray-value pixel and its surrounding pixels are used to determine the degree of smoothness and sharpness for embedding the secret data. If the difference values are large in a block, and the block is located in the sharp area then more data can be embedded. On the other hand, if the block is located in the smooth area less data can be embedded. The multi-pixel differencing method is employed in our scheme. We also propose the pixel-value shifting method to increase the image quality. The experimental results show that our scheme has a large embedding capacity without creating a noticeable distortion.

This paper proposes a new adaptive least-significant- bit (LSB) steganographic method using pixel-value differencing (PVD) that provides a larger embedding capacity and imperceptible stegoimages. The method exploits the difference value of two consecutive pixels to estimate how many secret bits will be embedded into the two pixels. Pixels located in the edge areas are embedded by a k-bit LSB substitution method with a larger value of k than that of the pixels located in smooth areas. The range of difference values is adaptively divided into lower level, middle level, and higher level. For any pair of consecutive pixels, both pixels are embedded by the k-bit LSB substitution method. However, the value k is adaptive and is decided by the level which the difference value belongs to. In order to remain at the same level where the difference value of two consecutive pixels belongs, before and after embedding, a delicate readjusting phase is used. When compared to the past study of Wu et al.'s PVD and LSB replacement method, our experimental results show that our proposed approach provides both larger embedding capacity and higher image quality.