10818775
Zheng and Seberry’s public key encryption scheme revisited
In this paper, we prove that a slightly modified version of Zheng and Seberry’s public key encryption scheme presented at Crypto ’92 is secure against adaptive chosen ciphertext attacks in the random oracle model, assuming the Gap Diffie–Hellman problem is intractable. A further contribution of this paper is to show that Soldera, Seberry, and Qu’s recent security analysis of Zheng and Seberry’s scheme is in fact flawed.
9346791
On the Security of RSA with Primes Sharing Least-Significant Bits
Abstract.We investigate the security of a variant of the RSA public-key cryptosystem called LSBS-RSA, in which the modulus primes share a large number of least-significant bits. We show that low public-exponent LSBS-RSA is inherently resistant to Partial Key Exposure (PKE) attacks in which least-significant bits of the secret exponent are revealed to the attacker, and in particular that the Boneh-Durfee-Frankel PKE attack [5] on low public-exponent RSA is less effective for LSBS-RSA systems than for standard RSA. On the other hand, we show that large public-exponent LSBS-RSA is more vulnerable to such attacks than standard RSA. An application to server-aided RSA signature generation is proposed.
105147
Digital Watermarking Robust Against JPEG Compression
Digital watermarking has been considered as an important technique to protect the copyright of digital content. For a digital watermarking method to be effective, it is essential that a watermark embedded in a still or moving image resists against various attacks ranging from compression, filtering to cropping. As JPEG is a dominant still image compression standard for Internet applications, digital watermarking methods that are robust against the JPEG compression are especially useful. Most digital watermarking methods proposed so far work by modulating pixels/coefficients without considering the quality level of JPEG, which renders watermarks readily removable. In this paper, we propose a new method that actively uses the JPEG quality level as a parameter in embedding a watermark into an image. A useful feature of the new method is that the watermark can be extracted even when the image is compressed using JPEG.
9394465
A Signcryption Scheme Based on Integer Factorization
Signcryption is a public-key cryptographic primitive introduced by Zheng, which achieves both message confidentiality and nonrepudiatable origin authenticity, at a lower computational and communication overhead cost than the conventional 'sign-then-encrypt' approach. We propose a new signcryption scheme which gives a partial solution to an open problem posed by Zheng, namely to find a signcryption scheme based on the integer factorization problem. In particular, we prove that our scheme is existentially unforgeable, in the random oracle model, subject to the assumption that factoring an RSA modulus N = pq (with p and q prime) is hard even when given the additional pair (g; S), where g ∈ Z*N is an asymmetric basis of large order less than a bound S=2 « √N.
6962958
Characterising user data protection of software components
Proposes a scheme to characterise non-functional security properties that are embedded within the functionality of software components. The security properties may be attached to various aspects of a component, such as resource allocation, user data protection, communication, and so on. In this paper, we are particularly interested in characterising the user data protection of software components. It is often reported that software components usually suffer from security and reliability problems. It is now widely recognised that the characterisation of the security properties of software components is an important issue to boost the confidence and trust in component technology. To address this issue, the characterisation of the security properties of components is the first challenging step. The work proposed in this paper is partially based on the functional requirements defined in the Common Criteria for Information Technology Security Evaluation endorsed by NIST. The applicability of the proposed scheme is demonstrated with a simple example.
14223982
Statistical Database Modeling for Privacy Preserving Database Generation
Testing of database applications is of great importance. Although various studies have been conducted to investigate testing techniques for database design, relatively few efforts have been made to explicitly address the testing of database applications which requires a large amount of representative data available. As testing over live production databases is often infeasible in many situations due to the high risks of disclosure of confidential information or incorrect updating of real data, in this paper we investigate the problem of generating synthetic database based on a-priori knowledge about production database. Our approach is to fit general location model using various characteristics (e.g., constraints, statistics, rules) extracted from production database and then generate synthetic data using model learnt. As characteristics extracted may contain information which may be used by attacker to derive some confidential information, we present a disclosure analysis method which is based on cell suppression technique. Our method is effective and efficient to remove aggregate private information during data generation.
6106156
Unsupervised Image Segmentation with Fuzzy Connectedness
In this paper, we report a method to do unsupervised image segmentations based on fuzzy connectedness with scale space theory. A new measure for doing segmented regions' mergence is also proposed. The method can be used in many applications like content based image retrieval and medical image analysis, etc.
7580725
Kosha: A Peer-to-Peer Enhancement for the Network File System
The storage needs of modern scientific applications are growing exponentially, and designing economical storage solutions for such applications – especially in Grid environments – is an important research topic. This work presents Kosha, a system that aims to harvest redundant storage space on cluster nodes and user desktops to provide a reliable, shared file system that acts as a large distributed storage. Kosha utilizes peer-to-peer (p2p) mechanisms to enhance the widely-used Network File System (NFS). P2P storage systems provide location transparency, mobility transparency, load balancing, and file replication – features that are not available in NFS. On the other hand, NFS provides hierarchical file organization, directory listings, and file permissions, which are missing from p2p storage systems. By blending the strengths of NFS and p2p storage systems, Kosha provides a low overhead storage solution. Our experiments show that compared to unmodified NFS, Kosha introduces a 3.3% fixed overhead and 4.5% additional overhead as nodes are increased from two to sixteen. For larger number of nodes, the additional overhead increases slowly. Kosha achieves load balancing in distributed directories, and guarantees $99.99\%$ or better file availability.
10569326
Intelligent compliant motion control
The role of a compliant motion scheme is to control a robot manipulator in contact with its environment. By accommodating with the interaction force, the manipulator can be used to accomplish tasks that involve constrained motions. This paper presents a new work on the compliant motion control for position-controlled manipulator. A new method for achieving efficient interaction between the manipulator and its environment is developed. The interaction force is reduced using a quadratic cost function. In this method, the compliance is formulated as function of the interaction force. An adaptive element is used to update the compliance. The stability of the system is investigated using the Lyapunov approach. Experiments are conducted in our laboratory to demonstrate the use of such scheme.
9136723
Biped Locomotion by Reduced Ankle Power
Power reduction in the ankle joints of a biped robot is considered inthis paper. Ankles of human beings have small torque and are veryflexible within a certain range of motion (very stiff near and beyondthis range). This characteristic makes foot landing soft and gives agood contact between its sole and the ground. This feature can beimplemented in a biped robot by using a small actuator for the anklejoints. A small actuator consumes less energy and reduces the weightof the leg. With less power in the ankle joints, robot walkingbecomes more difficult to control. This problem can be solved byproviding a feedback control mechanism as presented in this paper. Thecontrol mechanism uses the motion of the body and the swinging leg toeliminate instability caused by the weak ankle. Two locomotionexamples, standing and walking, were investigated respectively toshow the validity of the proposed control scheme. In standing, thecontrol input is the displacement of the ankle joint of thesupporting leg. The control mechanism decides the bending angle ofthe body and the position of the swinging leg. For walking, only thebending angle of the body is used to avoid the discontinuity of thecontrol input. Experimental results are presented to show theeffectiveness of the control mechanism.
2310959
XKvalidator: a constraint validator for XML
The role of XML in data exchange is evolving from one of merely conveying the structure of data to one that also conveys its semantics. In particular, several proposals for key and foreign key constraints have recently appeared, and aspects of these proposals have been adopted within XMLSchema.In this paper, we examine the problem of checking keys and foreign keys in XML documents using a validator based on SAX. The algorithm relies on an indexing technique based on the paths found in key definitions, and can be used for checking the correctness of an entire document (bulk checking) as well as for checking updates as they are made to the document (incremental checking). The asymptotic performance of the algorithm is linear in the size of the document or update. Furthermore, experimental results demonstrate reasonable performance.