26482984
Resettable Zero Knowledge with Concurrent Soundness in the Bare Public-Key Model under Standard Assumption
In this paper we present the firstconstant round resettable zero knowledge arguments with concurrent soundness for $\mathcal{NP}$ in the bare public-key (BPK for short) model assuming only collision-resistant hash functions against polynomial-timeadversaries. This resolves the problem whether there exist such protocols for $\mathcal{NP}$ in BPK model without assuming sub-exponential hardness. In our protocol, the resettable zero knowledge is demonstrated via a black-box simulator, while the concurrent soundness is proved by using the malicious prover strategy in non-black-boxmanner.
29420806
Strengthening QIM-Based Watermarking by Non-uniform Discrete Cosine Transform
Being extremely precise and at a low loss of perceptual quality, the attacks of value modification and optimized noise reduction still threaten the watermarking based on quantization index modulation (QIM). To resist them, the paper constructs a non-uniform discrete cosine transform (NDCT), and brings out an NDCT-QIM watermarking scheme, which embeds a watermark in a private NDCT domain with the parameters of NDCT as a secret key. The technique blinds the value modification by dispersing the attacking signal and changing its energy in the embedded domain. Because of the variable power spectrum of a watermark, the noise reduction becomes non-optimal. Some other advantages, including the ease of embedding, computational simplicity, etc., can also be acquired or maintained by the use of NDCT.
26263616
Developing a Formal Design Analysis Framework
15968998
A formal approach for architectural modeling and prototyping of distributed real-time systems
For complex software systems, a central design concern is the system architecture. The systematic treatment of architectural specification and refinement is a proper basis for an engineering approach to system design. However, conventional Petri net models do not provide adequate abstractions for architectural specification, because their primary concern is behavior modeling and analysis. As an attempt to address this problem, we present a formal model called NOAM (Net-based and Object-based Architectural Model) for architectural specification and prototyping of real-time distributed systems. Building on the existing contributions from Petri nets, NOAM not only supports precise specification of real-time behavior embodied in a system architecture, but also provides a framework for systematic architectural refinement and exploration. Special focus is placed on using the formal model and our support environment to prototype NOAM specifications, and to meet real-time constraints.
44761977
Executable Specification and Analysis for the Design of Concurrent Object-Oriented Systems
This paper investigates the analysis of concurrent OO designs using a formal, executable specification technique called G-Net. After presenting an overview of the G-Net technique, we show how to use the G-Net notation to specify the concurrent OO systems. A formal transformation technique, which translates a G-Net specification to a semantically equivalent PrT-net, is presented. The resultant PrT-net can then be formally analyzed. The practical significance of this approach in fault-tolerant systems and distributed multimedia systems design is discussed.
30407300
A G-Net Model for Knowledge Representation and Reasoning
The G-net model for G-type knowledge representation is introduced. It is capable of modeling both static semantic knowledge and dynamic control knowledge, combining them into a loosely coupled, mixed-type knowledge hierarchy. Four reasoning algorithms for the G-net model are proposed: inheritance reasoning and recognition reasoning for semantic knowledge, event-driven reasoning for dynamic knowledge, and control table reasoning for coordination and control in a mixed-type knowledge hierarchy. Based on the knowledge-table representation, the G-net model expresses the constraints and relationships among knowledge objects explicitly so that reasoning algorithms can be implemented efficiently. Applications to information systems prototyping are discussed. >
8350188
Constraint Propagation And Progressive Verification For Component-Based Process Model
System assembly is one of the major issues in engineering complex component-based systems. This is especially true when heterogeneous, COTS and GOTS distributed systems, typical in industrial applications, are involved. The goal of system assembly is not only to make constituent components work together, but also to ensure that the components as a whole behave consistently and guarantee certain end-to-end properties. Despite recent advances, there is a lack of understanding about software composability, as well as theory and techniques for checking and verifying component-based systems. A theory of software system constraints about components, their environment and about system as a whole is the necessary foundation toward solid understanding of the composability of component-based systems. In this paper, we present a systematic approach for constraint specification and constraint propagation in concert with design refinement with a novel technique to ensure consistency between system-wide and component constraints in a design composition process of component-based systems. The consistent constraint propagation is used in our approach to drive progressive verification of the design. It allows us to verify overall design composition without interference of internal details of component designs. Verification is done separately at architectural and component levels without having to compose results of component analyses. A component can be safely replaced with alternative design without re-verifying the overall system composition so long as the replacement conforms to the corresponding interface and component constraint(s).