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Yakovlev, Victor; Korzhik, Valery; Bakaev, Mihail; MoralesLuna, Guillermo
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1 Citations
We consider the informationtheoretic secure key distribution problem (KDP) over noisy binary symmetric channels with public discussion and in the presence of an active adversary. There are several versions of such protocols proposed by Maurer, Wolf, Renner, Dodis, Reyzin et al. We describe two new versions of KDP for the same channel model and with the use of extractors as a mean of privacy amplification but with the goal to maximize the key rate under an optimization of the protocol parameters. There are two novelties in solution of KDP: we get the extractor’s seed directly from the distributed initial strings and we prove the main results in terms of explicit estimates without the use of the uncertain symbols O, Ω, Θ. Both asymptotic and nonasymptotic cases are presented. It is shown that the extractors can be superior to conventional hashing for very large lengths of initially distributed strings.
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MoralesLuna, Guillermo
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1 Citations
We use a simple epistemic logic to pose problems related to relational database design. We use the notion of attribute dependencies, which is weaker than the notion of functional dependencies, to perform design tasks since it satisfies Armstrong axioms. We discuss also the application of the simple epistemic logic to privacy protection and to statistical disclosure.
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Korjik, Valeri; MoralesLuna, Guillermo
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1 Citations
We consider a scenario where information hiding (IH) is performed through noisy channels. There may arise different situations but one of the most common is the case where the legal IH channel is superior to the attacker IH channel. If a special randomized encoding is used by legal users then it is possible to hide information in the noisy components of the cover message. At the same time, the randomized encoding prevents the secret message to be removed from the stegomessage without any significant distortion of the cover message. If a legal decoder of IH knows the cover message, a randomized encoding procedure does not prevent the error correction of the secret message at the receiving side. The special problem of IH  how to distinguish any binary periodic repetitive sequence from truly random binary noise received on noisy channels  is presented. Application of the randomized encoding technique makes a solution to this problem more difficult and hence complicates a traffic analysis. We consider also how is it possible to “camouflage” IH by natural channel noises independently of the properties of the cover messages probability space, and the application of WM in combination with randomized encoding dedicated to the utilization of noisy channels. If an attacker tries to remove WM by adding binary noise then an expansion of errors in the cover message results.
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OlmedoAguirre, José Oscar; Rosa, Mónica Rivera; MoralesLuna, Guillermo
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System modeling, analysis and visualization are becoming a common practice for the design of distributed intelligent systems since the wide adoption of the Unified Modeling Language (UML). However, UML cannot describe important behavioral properties such as context awareness as required for ubiquitous computing. In this paper, we present Context Aware UML Sequence diagrams (CA UMLS), an experimental visual programming language that extends UML sequence diagrams with data/ object spaces to represent computational context awareness. The programming language provides the means to describe the eventconditionaction (ECA) rules that govern complex nomadic user behavior and to visualize their effect. The ECA rules are compiled into common concurrent programming abstractions by introducing structuring notions of object creation, synchronization, and communication, along with sequential and selective composition of simpler rules. The contribution of this work is in providing programming abstractions that facilitate the design of contextaware applications for ubiquitous and nomadic computing.
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Korzhik, Valery; MoralesLuna, Guillermo
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1 Citations
We consider a cryptographic scenario where some center broadcasts a random binary string to Alice, Bob and Eve over binary symmetric channels with bit error probabilities ε_{A}, ε_{B} and ε_{E} respectively. Alice and Bob share no secret key initially, and their goal is to generate, after public discussion, a common informationtheoretically secure key facing an active eavesdropper Eve. Under the condition ε_{A}<ε_{E} and ε_{B}<ε_{E}, code authentication (CA) can be used as part of a public discussion protocol to solve this problem. This authentication exploits parts of substrings received by Alice and Bob from the broadcasting center as authenticators to messages transmitted in a public discussion. Unfortunately, it happens to be ineffective because it produces a key of small length. We propose a hybrid authentication (HA) that combines both keyless code authentication and key authentication based on an almost strong universal class of hash functions. We prove a theorem that allows estimation of the performance evaluation of hybrid authentication. The selection algorithm for the main HA parameters, given security and reliability thresholds, is presented in detail.
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CruzSantos, William; MoralesLuna, Guillermo
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1 Citations
We study the Hamiltonians resulting from the Adiabatic Quantum Computing treatment of the Satisfiability Problem SAT. We provide respective procedures for explicit calculation of the involved Hamiltonians. The statement of the ending Hamiltonians allows us to pose a variant of SAT which is also NPcomplete.
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García, Edscott Wilson; MoralesLuna, Guillermo
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In the case of desktop grids, a single hardwaredetermined latency and constant bandwidth between processors cannot be assumed without incurring in unnecessary error. The actual network topology is determined not only by the physical hardware, but also by the instantaneous bandwidth availability for parallel processes to communicate. In this paper we present a novel task assignment scheme which takes the dynamic network topology into consideration along with the traditionally evaluated variables such as processor availability and potential. The method performs increasingly better as the grid size increases.
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Korzhik, Valery; Imai, Hideki; Shikata, Junji; MoralesLuna, Guillermo; Gerling, Ekaterina
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4 Citations
It is very common to use the notion of relative entropy (or KullbackLeibler divergence) as a measure for the discrimination difficulty among the hypotheses testing of presence and absence within a steganographic system. Relative entropy is not a symmetric function and sometimes it is very hard to compute its values. We propose to customize the notion of Bhattacharyya distance to the solution of the same problem. The main properties of Bhattacharyya distance are presented. We show applications of this new steganographic system security criterion within the model with a Gaussian colored covertext and within spreadspectrum watermarking by a white Gaussian sequence.
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OlmedoAguirre, Oscar; EscobarVázquez, Karina; AlorHernández, Giner; MoralesLuna, Guillermo
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2 Citations
As XML is becoming widely accepted as a mean of storing, searching and extracting information, a larger number of Web applications will require conceptual models and administrative tools to organize their collections of documents. Recently, eventconditionaction (ECA) rules have been proposed to provide reactive functionality into XML document databases. However, logical inference mechanisms to deliver multiagentbased applications remain unconsidered in those models. In this paper, we introduce ADM, an active deductive XML database model that extends XML with logical variables, logical procedures and ECA rules. ADM has been partially implemented in an open distributed coordination architecture written in Java. Besides of coupling the rational and reactive behavioral aspects into a simple and uniform model, a major contribution of this work is the introduction of sequential and parallel rule composition as an effective strategy to address the problem of scheduling rule selection and execution.
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Korzhik, Valery; MoralesLuna, Guillermo; Lee, Moon Ho
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6 Citations
There are several steganography techniques (e.g. linguistic or least significant bit embedding) that provide security but no robustness against an active adversary. On the other hand it is rather well known that the spreadspectrum based technique is robust against an active adversary but it seems to be insecure against a statistical detection of stegosignal. We prove in this paper that actually this is not the case and that there exists an stegosystem that is asymptotically both secure to statistical detection and robust against a jamming of stegosignal by an active adversary. We call such stegosystems quasiperfect whereas we call them perfect if in addition the data rate of secret information is asymptotically constant. We prove that perfect stegosystems do not exist for both blind and informed decoders. Some examples using the simplex and the ReedMuller codes jointly with stegosystems are given.
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MoralesLuna, Guillermo
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#kSAT is a complex problem equivalent to calculate the cardinalities of the null sets of conjunctive forms consisting of clauses with an uniform length. Each such null set is the union of linear varieties of uniform dimension in the hypercube. Here we study the class of sets in the hypercube that can be realized as such null sets. We look toward to characterize their cardinalities and the number of ways that they can be expressed as unions of linear varieties of uniform dimension. Using combinatorial and graph theory argumentations, we give such characterizations for very extremal values of k, either when it is very small or close to the hypercube dimension, and of the number of clauses appearing in an instance, either of value 2, or big enough to get a contradiction.
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OlmedoAguirre, Oscar; EscobarVázquez, Karina; AlorHernández, Giner; MoralesLuna, Guillermo
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As XML is becoming widely accepted as a mean of storing, searching and extracting information, a larger number of Web applications will require conceptual models and administrative tools to organize their collections of documents. Recently, eventconditionaction (ECA) rules have been proposed to provide reactive functionality into XML document databases. However, logical inference mechanisms to deliver multiagentbased applications remain unconsidered in those models. In this paper, we introduce ADM, an active deductive XML database model that extends XML with logical variables, logical procedures and ECA rules. ADM has been partially implemented in an open distributed coordination architecture written in Java. Besides of coupling the rational and reactive behavioral aspects into a simple and uniform model, a major contribution of this work is the introduction of sequential and parallel rule composition as an effective strategy to address the problem of scheduling rule selection and execution.
Keywords: XML, Semantic Web, Deductive Databases, Active Databases.
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By
Korjik, Valeri; MoralesLuna, Guillermo; Balakirsky, Vladimir B.
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3 Citations
Secret key agreement protocol between legal parties based on reconciliation and privacy amplification procedure has been considered in [2]. The so called privacy amplification theorem is used to estimate the amount of Shannon’s information leaking to an illegal party (passive eavesdropper) about the final key.We consider a particular case where one of the legal parties (Alice) sends to another legal party (Bob) a random binary string x through a binary symmetric channel (BSC) with bit error probability ε_{m} while an eavesdropper (Eve) receives this string through an independent BSC with bit error probability ε_{w}. We assume that ε_{m} < ε_{w} and hence the main channel is superior to the wiretap channel. To reconcile the strings between legal parties Alice sends to Bob through noiseless channel the check string y based on some good error correcting code. Since this transmission is completely public Eve can eavesdrop it and therefore this extra information has to be taken into account in an estimation of the information leaking to Eve about the final key. In [3] an inequality has been proved to upper bound the information of Eve in such scenario. The main contribution of the running paper is to improve this inequality and hence to enhance the privacy amplification theorem. We present also bounds for the probability of false reconciliation when the check symbols of the linear code are transmitted through noiseless channel. The presented results can be very useful when considering the nonasymptotic case.
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Korzhik, Valery; MoralesLuna, Guillermo; Marakova, Irina; PatiñoRuvalcaba, Carlos
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We consider a private zerobit watermark (WM) system in which an unauthorized removal of the WM is restricted by a linear filtering of the watermarked message combined with additive noise attack. It is assumed that a WM detector knows both the original cover message (CM) and the pulse (or frequency) response of the attack filter. The formulas to calculate the WMmissing and WMfalse alarm probabilities are developed and proved. We conclude that whenever some filtering of the watermarked message is yet acceptable with respect to CM quality then there results in a degradation of the WM system even if the designer of the WM uses an optimal signal. This fact is different than most that can be found at current WM literature. The main properties of a WM system under a filtering and additive noise attack condition are confirmed by simulations of the watermarked images.
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OlmedoAguirre, Oscar; MoralesLuna, Guillermo
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We introduce the declarative programming language Indeed that uses both deduction and interaction through multiagent system applications. The language design is addressed by providing a uniform programming model that combines two refinements of resolution along with some control strategies to introduce statebased descriptions. We show that the logical calculus in which the computational model is based is sound and complete. Finally, we compare our approach to others proposed for coupling interaction with automated deduction.
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By
RodríguezHenríquez, Francisco; MoralesLuna, Guillermo; Saqib, Nazar A.; CruzCortés, Nareli
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20 Citations
In this contribution, we derive a novel parallel formulation of the standard Itoh–Tsujii algorithm for multiplicative inverse computation over the field GF(2^{m}). The main building blocks used by our algorithm are: field multiplication, field squaring and field square root operators. It achieves its best performance when using a special class of irreducible trinomials, namely, P(x) = x^{m} + x^{k} + 1, with m and k odd numbers and when implemented in hardware platforms. Under these conditions, our experimental results show that our parallel version of the Itoh–Tsujii algorithm yields a speedup of about 30% when compared with the standard version of it. Implemented in a Virtex 3200E FPGA device, our design is able to compute multiplicative inversion over GF(2^{193}) after 20 clock cycles in about 0.94 μS.
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By
Korzhik, Valery; Fedyanin, Ivan; Godlewski, Artur; MoralesLuna, Guillermo
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1 Citations
It is introduced a new steganalytic method based on investigation of statistical properties of the extracted encrypted messages. It is assumed that the message is encrypted before embedding by some sufficiently strong cipher. The extracted messages are exposed to the testing on pseudorandomness, namely to NISTtests. When passing these tests, the tested objects are assumed stegoobjects, otherwise as cover objects. Support vector machine methodology is used to improve the testing process. Experiments demonstrate that the proposed algorithm is able to detect stegosystems as LSBbased embedding (both replacing and matching), with pseudorandom walks given by stegokeys, and with matrix embedding based on Hamming codes with reasonable reliability.
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Korzhik, Valery; Yakovlev, Viktor; MoralesLuna, Guillermo; Chesnokov, Roman
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4 Citations
We consider a cryptographic scenario of two honest parties which share no secret key initially, but their final goal is to generate an informationtheoretical secure key. In order to reach this goal they use assistance ofsome trusted center (as a satellite) that broadcasts a random string to legal users over noisy channels. An eavesdropper is able to receive also this string over another noisy channel. After an execution of the initialization phase, legal parties use discussion over noiseless public channels existing between them. The eavesdropper can intervene in the transmission and change the messages transmitted by legal parties. Thus, it is necessary to provide authentication of these messages. Otherwise the legal parties may agree a false key with the eavesdropper instead. In this paper we develop a concept of authentication based on noisy channels and present a performance evaluation of authentication procedures both for nonasymptotic and asymptotic cases.
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GarciaRobledo, Alberto; DiazPerez, Arturo; MoralesLuna, Guillermo
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1 Citations
AllSources BFS (ASBFS) is the main building block in a variety of complex network metric algorithms, such as the average path length and the betweenness centrality. However, ASBFS calculations involve as many full BFS traversals as the total number of vertices, rendering ASBFS impractical on commodity systems for realworld graphs with millions of vertices and links. In this paper we present our experience with the acceleration of ASBFS graph metrics on multicore HPC clusters by outlining hybrid coarsegrain parallel algorithms for computing the average pathlength, the diameter and the betweenness centrality of complex networks in a lockfree fashion. We report speedups of up to 171
$$\times $$
on a heterogeneous cluster of 12core Intel Xeon and 32core AMD Opteron multicore nodes; as well as resource utilizations of up to 75%.
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By
KuCauich, Juan Carlos; MoralesLuna, Guillermo
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We introduce three new constructions of systematic authentication codes over finite fields and Galois rings. Our first construction uses resilient functions over finite fields and provides optimal impersonation and substitution probabilities. Our two other constructions are defined over Galois rings: one is based on resilient maps attaining optimal probabilities as well, while the other is based on maps with maximum Fourier transforms. For the special case of characteristic
$$p^2$$
, the maps used on our third construction are bent. Furthermore, we give a generalised construction for the case of characteristic
$$p^s$$
, with
$$s \ge 2$$
. The second and third codes over Galois rings, restricted to the particular case of Galois fields, are different than the first code introduced in this paper: the corresponding source and tag spaces differ, and the encoding maps classes are pairwise different.
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