Shiuh-Jeng Wang

A data hiding scheme using the varieties of pixel-value differencing in multimedia images

In this paper, a capacity promoting technique is proposed for embedding data in an image using pixel-value differencing (PVD). The PVD scheme embeds data by changing the difference value between two adjacent pixels so that more data is embedded into two pixels located in the edge area, than in the smooth area. In order to increase the embedding capacity, a new approach is proposed in this paper by searching edge area more flexibly. Instead of processing a pair of pixels at a time as proposed by Wu and Tsai, two pairs of pixels in a block are processed at the same time. In addition, we proposed a pixel-value shifting scheme to further increase the chances for embedding data. Our scheme exploits the edge areas more efficiently, thus leading to an increase in embedding capacity as shown by experimental results compared to Wu and Tsais method. Also, the embedding result of our scheme passes the Fridrich et al.s detection. Besides, according to the distribution of difference values, more practical range partitions are suggested for improving capacity.

Measures of retaining digital evidence to prosecute computer-based cyber-crimes

With the rapid growth of computer and network systems in recent years, there has also been a corresponding increase in cyber-crime. Cyber-crime takes many forms and has garnered much attention in the media, making information security a more urgent and important priority. In order to fight cyber-crime, criminal evidence must be gathered from these computer-based systems. This is quite different from the collection of conventional criminal evidence and can confuse investigators attempting to deal with the forensics of cyber-crime, highlighting the importance of computer forensics. In this paper, we offer solutions to guard against cyber-crime through the implementation of software toolkits for computer-based systems. In this way, those who engage in criminal acts in cyber-space can be more easily apprehended.

Internet forensics on the basis of evidence gathering with Peep attacks

The Peep attack is a variant application of a Botnet. This paper proposes a forensic procedure to analyze the attack behavior and explains how to carry out a computer crime investigation. We also discuss the well-known Botnets engaged in the execution of a Peep attack. In our paper, we describe a Peep attack on the Internet as the paradigm of how a cyber-investigator needs to act in the case of a Cybercrime. When cyber detectives prepare to investigate a break in cyber security, there are some issues they must keep in mind and face up to. It is crucial to swiftly preserve digital evidence and conduct forensic analysis that any useful evidence is seized soon after the cybercrime has been committed. Furthermore, there are two phases of digital forensic analysis to retrieve useful evidence when facing a cybercrime attack in our scheme. One phase observes the Internet attack action, and the other one introduces how to investigate each case in on-line analysis of sniffing packets and off-line examination of abnormal files. We believe that this analysis model is workable for any other form of Botnets presently being used.

Prediction-based Reversible Data Hiding Using Empirical Histograms in Images

This paper presents a multilevel reversible data hiding method based on histogram shifting which can recover the original image losslessly after the hidden data has been extracted from the stego-image. The method of prediction is adopted in our proposed scheme and prediction errors are produced to explore the similarity of neighboring pixels. In this article, we propose two different predictors to generate the prediction errors, where the prediction is carried out using the center prediction method and the JPEG-LS median edge predictor (MED) to exploit the correlation among the neighboring pixels. Instead of the original image, these prediction errors are used to hide the secret information. Moreover, we also present an improved method to search for peak and zero pairs and also talk about the analogy of the same to improve the histogram shifting method for huge embedding capacity and high peak signal-to-noise ratio (PSNR). In the one-level hiding, our method keeps image qualities larger than 53 dB and the ratio of embedding capacity has 0.43 bpp (bit per pixel). Besides, the concept with multiple layer embedding procedure is applied for obtaining high capacity, and the performance is demonstrated in the experimental results. From our experimental results and analytical reasoning, it shows that the proposed scheme has higher PSNR and high data embedding capacity than that of other reversible data hiding methods presented in the literature.

The IP address and time in cyber‐crime investigation

Purpose – Cyber technology is an extremely complicated field and the internet is being increasingly used as a place to commit crimes using personal computers, as well as network‐based computers. Although cyber investigation is still in the early stages of its development, the burgeoning use of the internet has increased the necessity for digital investigations. The purpose of this paper is to increase awareness of the latest in digital comparison for cyber‐crime investigation with the studies of IP‐address and time in computer systems.Design/methodology/approach – The approach to improving a cyber‐crime investigation is proposed in three stages: independent verification of digital clues, corresponding information from different sources, and preparation of a valid argument.Findings – If the police and other authorities do not stay on top of this problem, they may lose the battle to control this cyber‐crime explosion. The paper discusses how Taiwanese police investigate cyber‐crime and the experience is abl...

Remote table-based log-in authentication upon geometric triangle

Abstract In this paper, a mechanism is proposed to realize the table-based log-in authentication of user registrations in a remote network system. The stored table, called the generating key table, exists in a remote server, whose work is to validate whether the requesting user is legitimate or not. In our scheme, the keys planted in the generating key table are generated by geometric ways upon the triangular property on the two-dimensional coordinate plane, and are used for user authentication later. With our specific arrangements, the attacks of penetrating the stored table are prevented. Without loss of generality, in our scheme, the password can be chosen freely by the registering user, the dynamic operations for a users insertion, deletion and password change can be conducted, and the verification process is efficiently carried out as well. In addition, an invertible formula is pointed out to address the issue of table-based log-in authentication scheme. It can be the principle of devising such table-based log-in authentication scheme.

Privacy Concealments: Detective Strategies Unveiling Cyberstalking on Internet

Cyber world is developing with substantial advancement to enter into glorious future, but cybercrime has always been a disaster to this dream. Recent advancement in internet technologies has lead stalking to become cyber. Cyberstalking offenses have become diversified and technological advance. It creates social and mental disorders among victims. In order to improve the privacy of internet users against cyberstalking, a novel examination of action research is evaluated from a former event. With the guidance of this case study, we can discriminate normal social networking friends from the possible offenders. The initial results show that our approach is highly helpful. Curbing cyberstalking is a baffling task because of its newness and technological furtherance. It is believed that this study will clarify the obscure technological and social aspects of cyberstalking. In this paper, the proposed solutions can prohibit users from the risk of getting hurts, facilitate to cut down its roots and remove its foundation.

Capacity-Raising Steganography Using Multi-Pixel Differencing and Pixel-Value Shifting Operations

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.

Procedure guidance for Internet forensics coping with copyright arguments of client-server-based P2P models

Digital technology for transferring and controlling data has made substantial advances in recent years. It is important to protect innovations and to curb the copyright infringements in computer-based systems. Copyright is a legal framework of basic rights, allowing the owner to control or permit someone else to reproduce copyrighted works with commercial value. In recent decades, copyright violations have been moving into the criminal realm. This paper focuses on the procedure guidance of a fictitious P2P model, and discusses whether it contributes to the crime of copyright infringement in dealing with the distribution of digital content. From the perspective of internet forensics, the action research and the whole control mechanism, it is shown that a commercial server has full control over the P2P model.

Direct construction of a secret in generalized group-oriented cryptography

Abstract This paper proposes an efficient secret sharing scheme to simplify the secret construction in generalized group-oriented cryptography (GOC). In our secret sharing system, a secret can be reconstructed by a predetermined group of participants through authorized access. The generation of a shadow key for each designated participant in the group can be computed directly from the access tructure, without investigating the negative access structure, so that the secret may be revealed. Moreover, the security remains at the same level as the solving of a complicated factorization problem in the RSA assumption.