Yi-Hui Chen

Secret Hiding Mechanism Using QR Barcode

QR code is the commonly used two-dimensional (2D) barcode recently with the advantages of larger QR content and error correction capability. Based on the error correction property of QR code, we designed a secret hiding technique for QR barcode. The proposed scheme can conceal the secret data into the cover QR code without distorting the readability of QR content. That is, general browsers can read the QR content from the marked QR code for the sake of reducing attention. Only the authorized receiver can encrypt and retrieve the secret from the marked QR code. The secret payload of the designed scheme is adjustable. The scheme can convey larger secret into a QR code according to the selection of the QR version and the error correction level. The simulations demonstrate that the designed scheme is efficient and low computational complexity. The mechanism can be applied to the QR reader and mobile phone.

Design of a delegable SCORM conformant learning management system

Owing to the emergence and flourishing of the Internet, traditional teaching and educational activities are increasingly relying on the convenient and global-reaching networking technology. To boost up the development of e-learning technology and the interoperability of learning materials, the Advanced Distributed Learning Initiative defined a data-sharing standard, called the Sharable Content Object Reference Model (SCORM). In SCORM, because all learning materials (either SCOs or assets) are sharable, users cannot share (or delegate) parts or all of their teaching materials at will. This paper proposed an access control and delegation model for SCORM conformant learning management systems. Also, a prototype was developed to demonstrate the feasibility of the proposed model.

Hybrid secret hiding schemes based on absolute moment block truncation coding

This paper presents two secret hiding schemes based on absolute moment block truncation coding (AMBTC). One is for embedding secrets into complex blocks and the other one is for smooth blocks. As for the smooth blocks, the small variation of the block is adopted to define the embedding rule to minimize the distortion after data embedding. As for the complex blocks, the large variation of the block is used to embed more secrets while maintaining good visual quality. In the experiments, when compared to Ou and Sun’s scheme, the positive data is to confirm the higher capacity while preserving better visual quality.

QR code steganography with secret payload enhancement

Different from one-dimensional barcode, QR (quick response) code is a popular two-dimensional barcode due to the fact that it can carry greater data capacity and capable of resisting damage. The content of QR code can be easily revealed by barcode scanners. However, in the real world QR applications, the content could be private information, such as the e-ticket and e-coupon. The QR content should be protected to resist from unauthorized users/scanners. In this article, we explore the characteristic of QR barcode and design a QR barcode steganography mechanism. The private information can be embedded into a cover QR tag with high secret payload. For a normal scanner, a browser can only reveal the cover QR content from the marked QR code. Only the authorized user/scanner can further reveal the private secret from the marked QR tag. According to the experimental, the new algorithm can convey satisfactory secret payload in to a QR tag. The mechanism is efficient and feasible for private QR applications.

Diverse augmented reality exhibitions for differential users based upon private quick response code

The marker-based augmented reality (AR) system can produce 3D virtual object to satisfy the user interaction in the real-world. The marker is a tag/pattern and used to help the AR system to locate the corresponding virtual object on the scene. The marker, however, needs to be designed firstly and the recognition capability is limited. The exhibited virtual object and the marker, unfortunately, are linked in the AR system. Hence, such conventional AR system treats all users as the same role. In this article, we proposed a diversity AR system that can provide the differential virtual objects exhibitions for specific users, such as the joint member and different degree person. The new schemes exploited the error correction capability of QR barcode to conceal the individual secret stream of users into a QR marker. Consequently, the general user can only observe the normal 3D virtual object on the marked QR tag. The assigned members can further reveal the various virtual objects from the same QR tag. The proposed diverse AR system can distinguish different users from same QR marker and thereby exhibit the corresponding virtual objects. The new system is practical and can be widely applied in specific customer AR applications.

Secret sharing mechanism with cheater detection

Cheater detection is essential for a secret sharing approach which allows the involved participants to detect cheaters during the secret retrieval process. In this article, we propose a verifiable secret sharing mechanism that can not only resist dishonest participants but can also satisfy the requirements of larger secret payload and camouflage. The new approach conceals the shadows into a pixel pair of the cover image based on the adaptive pixel pair matching. Consequently, the embedding alteration can be reduced to preserve the fidelity of the shadow image. The experimental results exhibit that the proposed scheme can share a large secret capacity and retain superior quality.

RDF-Chord

Peer-to-peer (P2P) computing has gained great attention in both research and industrial communities. Although many P2P systems, such as CAN, Pastry, Chord, and Tapstry have been proposed, they only support exact-match lookups. To overcome the limitation, a new area of P2P research, called peer data management system (PDMS), has emerged. In PDMS, metadata were used for annotating resources to support complex queries. This paper proposed a hybrid PDMS called RDF-Chord. In RDF-Chord, a set of keys is ingeniously designed to significantly reduce the search spaces. In experiments, it shows that RDF-Chord is highly scalable and efficient, especially in range queries. Although many P2P systems, such as CAN, Pastry, Chord, and Tapstry have been proposed, they only support exact-match lookups.To overcome the limitation, a new area of P2P research, called peer data management system (PDMS), has emerged.In PDMS, metadata were used for annotating resources so that complex queries can be supported.To support efficient and complex queries, a flexible PDMS for P2P networks, called RDF-Chord, is proposed.In RDF-Chord, a set of keys is ingeniously designed to significantly reduce the search spaces.The experiments show that RDF-Chord is superior to RDFPeers, especially in range queries.

Tagged visual cryptography with access control

Visual cryptography is a way to encrypt the secret image into several meaningless share images. Noted that no information can be obtained if not all of the shares are collected. Stacking the share images, the secret image can be retrieved. The share images are meaningless to owner which results in difficult to manage. Tagged visual cryptography is a skill to print a pattern onto meaningless share images. After that, users can easily manage their own share images according to the printed pattern. Besides, access control is another popular topic to allow a user or a group to see the own authorizations. In this paper, a self-authentication mechanism with lossless construction ability for image secret sharing scheme is proposed. The experiments provide the positive data to show the feasibility of the proposed scheme.

Privacy image protection using fine-grained mosaic technique

Access control has been applied in multimedia database to preserve and protect the sensitive information. The past researches generate authorization rules to control the authorizations with fine-grained ability in social photos, meeting photos, promotional photos. However, it does not appropriate to use in some privacy scenarios (e.g., the increasing popularity of digital images being stored and managed by the service Google Street View). With low cost of maintenance, this paper integrates the data hiding technique into a fined-grained access control to mosaic the sensitive information as well as enable to recover the mosaic region if necessary. The experiments show the positive data to confirm the feasibility of the proposed scheme.

An Image Hiding Method by Linking Multiple Pixels with XOR Operator

In 2006, Mielikaines method partitioned pixels into pixel pairs. Two secret bits are embedded to a pixel pair through modifying only one pixel. After that, Chans method linked bits of two continuous pixels by using XOR operator to further reduce the pixel modifications. To generalize Chans method, in this paper, the concept of linking multiple pixels by using XOR operator is introduced. This way, Chans method becomes a special case of the proposed method. Moreover, through the proposed concept, modifying one pixel can further affect more results of XOR operator. That means the proposed method can embed more than two secret bits through modifying one pixel by adding/subtracting its pixel value to/from one. The procedures of secret embedding and extracting by linking three pixels are also represented in this paper. According to the experimental results, the pixel modifications in the proposed method are fewer than those in Mielikaines method and Chans method in most cases.