42696276
Concurrently Non-malleable Black-Box Zero Knowledge in the Bare Public-Key Model
In this paper we study the possibility of reducing the setup assumptions under which concurrent non-malleable zero knowledge protocol can be realized. A natural model choice is the bare public-key (BPK) model of [6], a model with very minimal setup assumptions. Our main contribution is to show in this model the following about constant-round concurrent non-malleable black-box zero-knowledge arguments. 
They can be constructed from any one-way function for any language in $\mathcal{NP}$. Here, our construction takes 5 rounds, and we can reduce it to a 4-round (round-optimal) argument under existence of one-way permutations. 
Under number-theoretic assumptions, they admit a time-efficient instantiation for some specific $\mathcal{NP}$ languages (e.g., all languages having efficient Σ protocols, for which we can implement our construction using only $\mathcal{O}(1)$ modular exponentiations). 
 
 
 
Compared to the non-black-box construction in a concurrent work of [OPV, ICALP 2008] in this model, our protocol (even the construction from one-way function) is significantly more time- and round-efficient and can be based on more general assumptions.
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.
6786934
Concurrently Non-Malleable Zero Knowledge in the Authenticated Public-Key Model
We consider a type of zero-knowledge protocols that are of interest for their practical applications within networks like the Internet: efficient zero-knowledge arguments of knowledge that remain secure against concurrent man-in-the-middle attacks. As negative results in the area of concurrent non-malleable zero-knowledge imply that protocols in the standard setting (i.e., under no setup assumptions) can only be given for trivial languages, researchers have studied such protocols in models with setup assumptions, such as the common reference string (CRS) model. This model assumes that a reference string is honestly created at the beginning of all interactions and later available to all parties (an assumption that is satisfied, for instance, in the presence of a trusted party). A growing area of research in Cryptography is that of reducing the setup assumptions under which certain cryptographic protocols can be realized. In an effort to reduce the setup assumptions required for efficient zeroknowledge arguments of knowledge that remain secure against concurrent man-in-the-middle attacks, we consider a model, which we call the Authenticated Public-Key (APK) model. The APK model seems to significantly reduce the setup assumptions made by the CRS model (as no trusted party or honest execution of a centralized algorithm are required), and can be seen as a slightly stronger variation of the Bare Public-Key (BPK) model from [8, 30], and a weaker variation of the registered public-key model used in [3]. We then define and study man-in-the-middle attacks in the APK model. Our main result is a constant-round concurrent non-malleable zero-knowledge argument of knowledge for any polynomial-time relation (associated to a language in NP), under the (minimal) assumption of the existence of a one-way function family. We also show time-efficient instantiations of our protocol, in which the transformation from a 3-round honest-verifier zero-knowledge argument of knowledge to a 4-round concurrently non-malleable zero-knowledge argument of knowledge for the same relation incurs only O(1) (precisely, a small constant) additional modular exponentiations, based on known number-theoretic assumptions. Furthermore, the APK model is motivated by the consideration of some man-inthe-middle attacks in models with setup assumptions that had not been considered previously and might be of independent interest. We also note a negative result with respect to further reducing the setup assumptions of our protocol to those in the (unauthenticated) BPK model, by showing that concurrently non-malleable zero-knowledge arguments of knowledge in the BPK model are only possible for trivial languages.
3145299
Resettable Zero Knowledge in the Bare Public-Key Model under Standard Assumption
In this paper we resolve an open problem regarding resettable zero knowledge in the bare public-key (BPK for short) model: Does there exist constant round resettable zero knowledge argument with concurrent soundness for $\mathcal{NP}$ in BPK model without assuming \emph{sub-exponential hardness}? We give a positive answer to this question by presenting such a protocol for any language in $\mathcal{NP}$ in the bare public-key model assuming only collision-resistant hash functions against \emph{polynomial-time} adversaries.
280798
Instance-Dependent Verifiable Random Functions and Their Application to Simultaneous Resettability
We introduce a notion of instance-dependent verifiable random functions(InstD-VRFs for short). Informally, an InstD-VRF is, in some sense, a verifiable random function [23] with a special public key, which is generated via a (possibly)interactiveprotocol and contains an instance y? L? {0,1}*for a specific NP language L, but the security requirements on such a function are relaxed: we only require the pseudorandomnessproperty when y? Land only require the uniquenessproperty when y? L, instead of requiring both pseudorandomness and uniqueness to hold simultaneously. We show that this notion can be realized under standard assumption. 
 
Our motivation is the conjecture posed by Barak et al.[2], which states there exist resettably-sound resettable zero knowledge arguments for NP. The instance-dependent verifiable random functions is a powerful tool to tackle this problem. We first use them to obtain two interesting instance-dependent argument systems from the Barak's public-coin bounded concurrent zero knowledge argument [1], and then, we 
 
 1 Construct the first(constant round) zero knowledge arguments for NP enjoying a certainsimultaneous resettability under standard hardness assumptions in the plain model, which we call bounded-class resettable ZK arguments with weak resettable-soundness Though the malicious party (prover or verifier) in such system is limited to a kind of bounded resetting attack, We put NO restrictions on the number of the total resets made by malicious party. 
 1 show that, under standard assumptions, if there exist public-coin concurrent zero knowledge arguments for NP, there exist the resettably-sound resetable zero knowledge arguments for NP.
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.
1577693
Managing security policies in a distributed environment using eXtensible markup language (XML)
of the growth of the Internet, much research has been done on application-level distributed authorization systems. Another area of research that is just as important, but has received little attention, is the management of security policies in a distributed environment. This paper describes practical concepts that can be employed in an enterprise environment for managing security policies using eXtensible Markup Language (XML). An example is given using our proposed concepts with Java 1 and Role-Based Access Control (RBAC) policies.
16690202
Formally analyzing software architectural specifications using SAM
In the past decade, software architecture has emerged as a major research area in software engineering. Many architecture description languages have been proposed and some analysis techniques have also been explored. In this paper, we present a graphical formal software architecture description model called software architecture model (SAM). SAM is a general software architecture development framework based on two complementary formalisms--Petri nets and temporal logic. Petri nets are used to visualize the structure and model the behavior of software architectures while temporal logic is used to specify the required properties of software architectures. These two formal methods are nicely integrated through the SAM software architecture framework. Furthermore, SAM provides the flexibility to choose different compatible Petri net and temporal logic models according to the nature of system under study. Most importantly, SAM supports formal analysis of software architecture properties in a variety of well-established techniques--simulation, reachability analysis, model checking, and interactive proving, In this paper, we show how to formally analyze SAM software architecture specifications using two well-known techniques--symbolic model checking with tool Symbolic Model Verifier, and theorem proving with tool STeP.
1196454
Resolving the Simultaneous Resettability Conjecture and a New Non-Black-Box Simulation Strategy
Canetti, Goldreich, Goldwasser, and Micali (STOC 2000) introduced the notion of resettable zero-knowledge proofs, where the protocol must be zero-knowledge even if a cheating verifier can reset the prover and have several interactions in which the prover uses the same random tape. Soon afterwards, Barak, Goldreich, Goldwasser, and Lindell (FOCS 2001) studied the closely related notion of resettable soundness, where the soundness condition of the protocol must hold even if the cheating prover can reset the verifier to have multiple interactions with the same verifier's random tape. The main problem left open by this work was whether it is possible to have a single protocol that is simultaneously resettable zero knowledge and resettably sound. We resolve this question by constructing such a protocol. At the heart of our construction is a new non-black-box simulation strategy, which we believe to be of independent interest. This new strategy allows for simulators which "marry'' recursive rewinding techniques (common in the context of concurrent simulation) with non-black-box simulation. Previous non-black-box strategies led to exponential blowups in computational complexity in such circumstances, which our new strategy is able to avoid.
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).
26263616
Developing a Formal Design Analysis Framework