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Triple Cyclic Codes Over 𝔽q + u𝔽q Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210104
Ting Yao; Shixin Zhu; Binbin PangLet R=𝔽q+u𝔽q, where q is a power of a prime number p and u2=0. A triple cyclic code of length (r,s,t) over R is a set that can be partitioned into three parts that any cyclic shift of the coordinates of the three parts leaves the code invariant. These codes can be viewed as R[x]submodules of R[x]/〈xr−1〉×R[x]/〈xs−1〉×R[x]/〈xt−1〉. In this paper, we study the generator polynomials and the minimum generating

Regular Expressions and Transducers Over AlphabetInvariant and UserDefined Labels Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201228
Stavros Konstantinidis; Nelma Moreira; Rogério Reis; Joshua YoungWe are interested in regular expressions and transducers that represent word relations in an alphabetinvariant way — for example, the set of all word pairs u,v where v is a prefix of u independently of what the alphabet is. Current software systems of formal language objects do not have a mechanism to define such objects. We define transducers in which transition labels involve what we call set specifications

Boosting Reversible Pushdown and Queue Machines by Preprocessing Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201215
Holger Bock Axelsen; Martin Kutrib; Andreas Malcher; Matthias WendlandtIt is well known that reversible finite automata do not accept all regular languages, that reversible pushdown automata do not accept all deterministic contextfree languages, and that reversible queue automata are less powerful than deterministic realtime queue automata. It is of significant interest from both a practical and theoretical point of view to close these gaps. We here extend these reversible

The BottomUp Position Tree Automaton and the Father Automaton Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201228
Samira Attou; Ludovic Mignot; Djelloul ZiadiThe conversion of a given regular tree expression into a tree automaton has been widely studied. However, classical interpretations are based upon a topdown interpretation of tree automata. In this paper, we propose new constructions based on Gluskov’s one and on the one by Ilie and Yu using a bottomup interpretation. One of the main goals of this technique is to consider as a next step the links

A New Hierarchy for Automaton Semigroups Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210106
Laurent Bartholdi; Thibault Godin; Ines Klimann; Camille Noûs; Matthieu PicantinWe define a new strict and computable hierarchy for the family of automaton semigroups, which reflects the various asymptotic behaviors of the stateactivity growth. This hierarchy extends that given by Sidki for automaton groups, and also gives new insights into the latter. Its exponential part coincides with a notion of entropy for some associated automata. We prove that the Order Problem is decidable

Synchronizing AlmostGroup Automata Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201215
Mikhail V. Berlinkov; Cyril NicaudIn this paper we address the question of synchronizing random automata in the critical settings of almostgroup automata. Group automata are automata where all letters act as permutations on the set of states, and they are not synchronizing (unless they have one state). In almostgroup automata, one of the letters acts as a permutation on n−1 states, and the others as permutations. We prove that this

State Complexity of Overlap Assembly Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201215
Janusz A. Brzozowski; Lila Kari; Bai Li; Marek SzykułaThe state complexity of a regular language Lm is the number m of states in a minimal deterministic finite automaton (DFA) accepting Lm. The state complexity of a regularitypreserving binary operation on regular languages is defined as the maximal state complexity of the result of the operation where the two operands range over all languages of state complexities ≤m and ≤n, respectively. We determine

NonSelfEmbedding Grammars, ConstantHeight Pushdown Automata, and Limited Automata Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201228
Bruno Guillon; Giovanni Pighizzini; Luca PrigionieroNonselfembedding grammars are a restriction of contextfree grammars which does not allow to describe recursive structures and, hence, which characterizes only the class of regular languages. A double exponential gap in size from nonselfembedding grammars to deterministic finite automata is known. The same size gap is also known from constantheight pushdown automata and 1limited automata to deterministic

The Ranges of Accepting State Complexities of Languages Resulting from Some Operations Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201230
Michal Hospodár; Markus HolzerWe examine the accepting state complexity, i.e., the minimal number of accepting states of deterministic finite automata for languages resulting from unary and binary operations on languages with accepting state complexity given as a parameter. This is a continuation of the work of [J. Dassow: On the number of accepting states of finite automata, J. Autom., Lang. Comb., 21, 2016]. We solve most of

Semilinearity of Families of Languages Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201228
Oscar H. Ibarra; Ian McQuillanTechniques are developed for creating new and general language families of only semilinear languages, and for showing families only contain semilinear languages. It is shown that for language families ℒ that are semilinear full trios, the smallest full AFL containing ℒ that is also closed under intersection with languages in NCM (where NCM is the family of languages accepted by NFAs augmented with

New Constructions of Codebooks Nearly Meeting the Welch Bound Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201119
Zexia Shi; Lei Sun; FangWei FuOptimal codebooks meeting the Welch bound with equality are desirable in many areas, such as direct spread code division multiple access communications, compressed sensing and so on. However, it is difficult to construct such optimal codebooks. There have been a number of attempts to construct codebooks nearly meeting the Welch bound. In this paper, we introduce a generic construction of codebooks

Infinite Families of 2Designs from a Class of Linear Codes Related to DembowskiOstrom Functions Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210118
Rong Wang; Xiaoni Du; Cuiling Fan; Zhihua NiuDue to their important applications to coding theory, cryptography, communications and statistics, combinatorial tdesigns have attracted lots of research interest for decades. The interplay between coding theory and tdesigns started many years ago. It is generally known that tdesigns can be used to derive linear codes over any finite field, and that the supports of all codewords with a fixed weight

Algorithmic Aspects of OuterIndependent Total Roman Domination in Graphs Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210118
Amit Sharma; P. Venkata Subba ReddyFor a simple, undirected graph G, a function h:V(G)→{0,1,2} which satisfies the following conditions is called an outerindependent total Roman dominating function (OITRDF) of G with weight h(V)=∑v∈Vh(v). (C1) For all q∈V with h(q)=0 there exists a vertex r such that qr∈E and h(r)=2, (C2) The induced subgraph with vertex set {p:h(p)≥1} has no isolated vertices and (C3) The induced subgraph with vertex

A Proof of Parikh’s Theorem via Dickson’s Lemma Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210113
Toshihiro KogaIn this paper, we give a proof of Parikh’s semilinear theorem via Dickson’s lemma. It is notable that our proof provides a clear separation between properties derived from Dickson’s lemma and tree decomposition for contextfree grammars.

An Exchanged 3Ary nCube Interconnection Network for Parallel Computation Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210113
Yali Lv; ChengKuan Lin; Guijuan WangThe interconnetion network plays an important role in a parallel system. To avoid the edge number of the interconnect network scaling rapidly with the increase of dimension and achieve a good balance of hardware costs and properties, this paper presents a new interconnection network called exchanged 3ary ncube (E3C). Compared with the 3ary ncube structures, E3C shows better performance in terms

On the Commutative Equivalence of Algebraic Formal Series and Languages Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210113
Arturo Carpi; Flavio D’AlessandroThe problem of the commutative equivalence of contextfree and regular languages is studied. Conditions ensuring that a contextfree language of exponential growth is commutatively equivalent with a regular language are investigated.

Search on a Line by Byzantine Robots Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210113
Jurek Czyzowicz; Konstantinos Georgiou; Evangelos Kranakis; Danny Krizanc; Lata Narayanan; Jaroslav Opatrny; Sunil ShendeWe consider the problem of faulttolerant parallel search on an infinite line by n robots. Starting from the origin, the robots are required to find a target at an unknown location. The robots can move with maximum speed 1 and can communicate wirelessly among themselves. However, among the n robots, there are f robots that exhibit byzantine faults. A faulty robot can fail to report the target even

AgglomerationBased Node Importance Analysis in WheelType Networks Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210113
Zeynep Nihan Berberler; Halil İbrahim Yildirim; Tolga İltüzer; İzzet TunçEvaluating the importance of nodes for complex networks is an important part of invulnerability research. In this paper, node importance analysis is conducted in wheelrelated networks by a method of evaluating node importance by node contraction based on network agglomeration in communication networks. Both degrees and positions of nodes are considered with this method. This method was also proved

Strict Linearizability and Abstract Atomicity Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210106
Tangliu Wen; Jie Peng; Jinyun Xue; Zhen You; Lan SongLinearizability is a commonly accepted consistency condition for concurrent objects. Filipović et al. show that linearizability is equivalent to observational refinement. However, linearizability does not permit concurrent objects to share memory spaces with their client programs. We show that linearizability (or observational refinement) can be broken even though a client program of an object accesses

Remarks on kClique, kIndependent Set and 2Contamination in Complementary Prisms Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210106
Priscila P. Camargo; Uéverton S. Souza; Julliano R. NascimentoComplementary prism graphs arise from the disjoint union of a graph G and its complement Ḡ by adding the edges of a perfect matching joining pairs of corresponding vertices of G and Ḡ. Classical graph problems such as Clique and Independent Set were proved to be NPcomplete on such a class of graphs. In this work, we study the complexity of both problems on complementary prism graphs from the parameterized

Hamiltonian Cycle Embeddings in Faulty Hypercubes Under the Forbidden Faulty Set Model Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210106
Chunfang Li; Shangwei Lin; Shengjia LiIn this paper, we study the faulttolerant capability of hypercubes with respect to the hamiltonian property based on the concept of forbidden faulty sets. We show, with the assumption that each vertex is incident with at least three faultfree edges, that an ndimensional hypercube contains a faultfree hamiltonian cycle, even if there are up to (4n−13) edge faults. Moreover, we give an example to

Cryptanalysis of CramerShoup Like Cryptosystems Based on Index Exchangeable Family Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210106
Jinhui liu; Yong Yu; Bo Yang; Jianwei Jia; Qiqi LaiThe CramerShoup (CS) like cryptosystem based on index exchangeable family (IEF) construction is a novel scheme introduced in Asiaccs 2016 by Li et al.. Its versatility was illustrated by building two public key encryption (PKE) schemes, a cramershoup encryption scheme based on IEFs, as well as an outsourcing technique based on nonabelian analog. However, the two schemes are not secure over the recommended

Timed Bounded Verification of Inclusion Based on Timed Bounded Discretized Language Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210106
Ikhlass Ammar; Yamen El Touati; John Mullins; Moez YeddesThe inclusion problem is one of the common problems in realtime systems. The general form of this problem is undecidable; however, the timebounded verification of inclusion problem is decidable for timed automata. In this study, we propose a new discretization technique to verify the inclusion problem. The proposed technique is applied to a nonZeno timed automaton with an upper bound that does not

Subgraphbased Strong Menger Connectivity of Hypercube and Exchanged Hypercube Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210106
Yihong Wang; ChengKuan Lin; Shuming Zhou; Tao TianLarge scale multiprocessor systems or multicomputer systems, taking interconnection networks as underlying topologies, have been widely used in the big data era. Fault tolerance is becoming an essential attribute in multiprocessor systems as the number of processors is getting larger. A connected graph G is called strong Menger (edge) connected if, for any two distinct vertices u and v, there are min{dG(u)

Super Ck and SubCk Connectivity of kAry nCube Networks Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20210104
Yuxing YangLet G be an undirected graph. An Hstructurecut (resp. Hsubstructurecut) of G is a set of subgraphs of G, if any, whose deletion disconnects G, where the subgraphs deleted are isomorphic to a certain graph H (resp. where for any T′ of the subgraphs deleted, there is a subgraph T of G, isomorphic to H, such that T′ is a subgraph of T). G is superHMconnected (resp. super subHMconnected) if the

Watson–Crick Jumping Finite Automata Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201116
Kalpana Mahalingam; Ujjwal Kumar Mishra; Rama RaghavanWatson–Crick jumping finite automata work on tapes which are double stranded sequences of symbols similar to that of Watson–Crick automata. The double stranded sequence is scanned in a discontinuous manner. That is, after reading a double stranded string, the automata can jump over some subsequence and continue scanning depending on the rule. Some variants of such automata are 1limited, No state,

Symbol Separation in Double Occurrence Words Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201110
Nataša Jonoska; Masahico Saito; Hwee Kim; Brad MostowskiA double occurrence word (DOW) is a word in which every symbol appears exactly twice. We define the symbol separation of a DOW w to be the number of letters between the two copies of a symbol, and the separation of w to be the sum of separations over all symbols in w. We then analyze relationship among size, reducibility and separation of DOWs. Specifically, we provide tight bounds of separations of

The Noninclusive Diagnosability of Hypercubes under the MM* Model Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201126
Tongtong Ding; Min Xu; Qiang ZhuDiagnosability is an important factor in multipleprocessor systems defined as the maximum number of faulty nodes that a system can recognize. In this paper, we propose a new form of diagnosability called noninclusive diagnosability that requires all faulty sets to be noninclusive. Furthermore, we study the noninclusive diagnosability of hypercubes under the MM* model for n≥1.

Distributed Approximation Algorithms for Steiner Tree in the CONGESTED CLIQUE Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201110
Parikshit Saikia; Sushanta KarmakarThe Steiner tree problem is one of the fundamental and classical problems in combinatorial optimization. In this paper we study this problem in the CONGESTED CLIQUE model (CCM) [29] of distributed computing. For the Steiner tree problem in the CCM, we consider that each vertex of the input graph is uniquely mapped to a processor and edges are naturally mapped to the links between the corresponding

Efficient Identification of Node Importance Based on Agglomeration in CycleRelated Networks Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201116
Aysun Asena Kunt; Zeynep Nihan BerberlerThe identification of node importance in complex networks is of theoretical and practical significance for improving network robustness and invulnerability. In this paper, the importance of each node is evaluated and important nodes are identified in cycles and related networks by node contraction method based on network agglomeration. This novel method considers both the degree and the position of

Additive Number Theory via Approximation by Regular Languages Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201010
Jason Bell; Thomas F. Lidbetter; Jeffrey ShallitWe prove some new theorems in additive number theory, using novel techniques from automata theory and formal languages. As an example of our method, we prove that every natural number >25 is the sum of at most three natural numbers whose base2 representation has an equal number of 0’s and 1’s.

Weak Cost Register Automata are Still Powerful Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201022
Shaull Almagor; Michaël Cadilhac; Filip Mazowiecki; Guillermo A. PérezWe consider one of the weakest variants of cost register automata over a tropical semiring, namely copyless cost register automata over ℕ with updates using min and increments. We show that this model can simulate, in some sense, the runs of counter machines with zerotests. We deduce that a number of problems pertaining to that model are undecidable, namely equivalence, upperboundedness, and semilinearity

A Pattern Logic for Automata with Outputs Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201005
Emmanuel Filiot; Nicolas Mazzocchi; JeanFrançois RaskinWe introduce a logic to express structural properties of automata with string inputs and, possibly, outputs in some monoid. In this logic, the set of predicates talking about the output values is parametric. We then consider three particular automata models (finite automata, transducers and automata weighted by integers here called sumautomata) and instantiate the generic logic for each of them. We

Projection for Büchi Tree Automata with Constraints between Siblings Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201005
Patrick Landwehr; Christof LödingWe consider an extension of tree automata on infinite trees that can use equality and disequality constraints between direct subtrees of a node. Recently, it has been shown that the emptiness problem for these kind of automata with a parity acceptance condition is decidable and that the corresponding class of languages is closed under Boolean operations. In this paper, we show that the class of languages

The Synchronizing Probability Function for Primitive Sets of Matrices Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201010
Costanza Catalano; Raphaël M. JungersMotivated by recent results relating synchronizing DFAs and primitive sets, we tackle the synchronization process and the related longstanding Černý conjecture by studying the primitivity phenomenon for sets of nonnegative matrices having neither zerorows nor zerocolumns. We formulate the primitivity process in the setting of a twoplayer probabilistic game and we make use of convex optimization

Decidability of Right OneWay Jumping Finite Automata Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201019
Simon Beier; Markus HolzerWe continue our investigation [S. Beier, M. Holzer: Properties of right oneway jumping finite automata. In Proc. 20th DCFS, LNCS, 2018] on (right) oneway jumping finite automata (ROWJFAs), a variant of jumping automata, which is an automaton model for discontinuous information processing. Here we focus on decision problems for ROWJFAs. It turns out that most problems such as, e.g., emptiness, finiteness

The Intersection Problem for Finite Semigroups Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201111
Lukas FleischerThe intersection problem for finite semigroups asks, given a set of regular languages, represented by recognizing morphisms to finite semigroups, whether there exists a word contained in their intersection. In previous work, it was shown that is problem is PSPACEcomplete. We introduce compressibility measures as a useful tool to classify the complexity of the intersection problem for certain classes

From TwoWay Transducers to Regular Function Expressions Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20201005
Nicolas Baudru; PierreAlain ReynierTransducers constitute a fundamental extension of automata. The class of regular word functions has recently emerged as an important class of wordtoword functions, characterized by means of (functional, or unambiguous, or deterministic) twoway transducers, copyless streaming string transducers, and MSOdefinable graph transformations. A fundamental result in language theory is Kleene’s Theorem,

A SpaceOptimal Hidden Surface Removal Algorithm for IsoOriented Rectangles Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200826
Andreas Kosmatopoulos; Athanasios Tsakalidis; Kostas TsichlasWe investigate the problem of finding the visible pieces of a scene of objects from a specified viewpoint. In particular, we are interested in the design of an efficient hidden surface removal algorithm for a scene comprised of isooriented rectangles. We propose an algorithm where given a set of n isooriented rectangles we report all visible surfaces in O((n+k)logn) time and linear space, where k

Multiuse Deterministic Public Key Proxy ReEncryption from Lattices in the AuxiliaryInput Setting Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200812
Juyan Li; Chunguang Ma; Zhen GuProxy ReEncryption (PRE) is a cryptographic primitive that allows a proxy to turn an Alice’s ciphertext into a Bob’s ciphertext on the same plaintext. All of the PRE schemes are public key encryption and semantic security. Deterministic Public Key Encryption (DPKE) provides an alternative to randomized public key encryption in various scenarios where the latter exhibits inherent drawbacks. In this

Linear Complexity of Binary Threshold Sequences Derived from Generalized Polynomial Quotient with PrimePower Modulus Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200831
Lianhua Wang; Xiaoni DuIn this paper, firstly we extend the polynomial quotient modulo an odd prime p to its general case with modulo pr and r≥1. From the new quotient proposed, we define a class of pr+1periodic binary threshold sequences. Then combining the Legendre symbol and Euler quotient modulo pr together, with the condition of 2p−1≢1(modp2), we present exact values of the linear complexity for p≡±3(mod8), and all

Weak Separation Problem for Tree Languages Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200826
Saeid Alirezazadeh; Khadijeh AlibabaeiForest algebras are defined for investigating languages of forests [ordered sequences] of unranked trees, where a node may have more than two [ordered] successors. They consist of two monoids, the horizontal and the vertical, with an action of the vertical monoid on the horizontal monoid, and a complementary axiom of faithfulness. A pseudovariety is a class of finite algebras of a given signature,

Almost Every nVertex Graph is Determined by Its 3log2nVertex Subgraphs Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200826
Ameneh FarhadianThis paper proves that almost every nvertex graph has the property that the multiset of its induced subgraphs on 3log2n vertices is sufficient to determine it up to isomorphism. That is, the probability that there exists two nvertex graphs with the same multiset of 3log2nvertex induced subgraphs goes to zero as n goes to infinity.

A New Study of Parikh Matrices Restricted to Terms Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200812
Zi Jing Chern; K. G. Subramanian; Azhana Ahmad; Wen Chean TehParikh matrices as an extension of Parikh vectors are useful tools in arithmetizing words by numbers. This paper presents a further study of Parikh matrices by restricting the corresponding words to terms formed over a signature. Some Mequivalence preserving rewriting rules for such terms are introduced. A characterization of terms that are only Mequivalent to themselves is studied for binary signatures

kFibonacci Cubes: A Family of Subgraphs of Fibonacci Cubes Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200826
Ömer Eğecioğlu; Elif Saygı; Zülfükar SaygıHypercubes and Fibonacci cubes are classical models for interconnection networks with interesting graph theoretic properties. We consider kFibonacci cubes, which we obtain as subgraphs of Fibonacci cubes by eliminating certain edges during the fundamental recursion phase of their construction. These graphs have the same number of vertices as Fibonacci cubes, but their edge sets are determined by a

Efficient Identification of kClosed Strings Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200826
Hayam Alamro; Mai Alzamel; Costas S. Iliopoulos; Solon P. Pissis; WingKin Sung; Steven WattsA closed string contains a proper factor occurring as both a prefix and a suffix but not elsewhere in the string. Closed strings were introduced by Fici (WORDS 2011) as objects of combinatorial interest. This paper addresses a new problem by extending the closed string problem to the kclosed string problem, for which a level of approximation is permitted up to a number of Hamming distance errors,

Efficient Algorithm for Computing the Triangle Maximizing the Length of Its Smallest Side Inside a Convex Polygon Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200706
Sanjib Sadhu; Sasanka Roy; Soumen Nandi; Subhas C. Nandy; Suchismita RoyGiven a convex polygon with n vertices, we study the problem of identifying a triangle with its smallest side as large as possible among all the triangles that can be drawn inside the polygon. We show that at least one of the vertices of such a triangle must coincide with a vertex of the polygon. We also propose an O(n2) time algorithm to compute such a triangle inside the given convex polygon.

On gExtra Conditional Diagnosability of Twisted Hypercubes under MM∗ Model Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200706
Shunzhe Zhang; Dong Li; Huiqing LiuConnectivity and diagnosability are important parameters in measuring the reliability and faulttolerance of an interconnection network G. The gextra conditional faulty set F is a faulty vertex set such that every component of G−F has at least g+1 vertices. The gextra connectivity κg(G) of a connected graph G is the minimum cardinality of a gextra conditional faulty set F of G such that G−F is disconnected

A Reduction of Integer Factorization to Modular Tetration Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200706
Markus HittmeirLet a,k∈ℕ. By 1a:=a and ka:=ak−1a, we denote the k th iterate of the exponential function x↦ax evaluated at a, also known as tetration. We demonstrate how an algorithm for evaluating tetration modulo natural numbers N could be used to compute the prime factorization of N and provide heuristic arguments for the efficiency of this reduction. Additionally, we prove that the problem of computing the squarefree

Palindromic Characteristic of Committed Graphs and Some Model Theoretic Properties Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200706
Ahmet ÇevikWe bring into attention the interplay between model theory of committed graphs (1regular graphs) and their palindromic characteristic in the domain of formal languages. We prove some model theoretic properties of committed graphs and then give a characterization of them in the formal language domain using palindromes. We show in the first part of the paper that the theory of committed graphs and the

Simplified Bounds on FHSs Set and Its Strictly Optimal Construction Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200626
Shanding Xu; Xiwang Cao; Jiafu Mi; Chunming TangFrequencyhopping sequences (FHSs) with favorite partial Hamming correlation properties are intensively needed in many synchronization and multipleaccess systems. Strictly optimal FHS sets are a kind of FHS sets which has optimal Hamming correlation for any correlation window. In this paper, firstly we present simplified representations of the generalized Lempel–Greenberger bound on the partial Hamming

On the Membership Problem of Permutation Grammars — A Direct Proof of NPCompleteness Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200626
Benedek NagyOne of the most essential classes of problems related to formal languages is the membership problem (also called word problem), i.e., to decide whether a given input word belongs to the language specified, e.g., by a generative grammar. For contextfree languages the problem is solved efficiently by various wellknown parsing algorithms. However, there are several important languages that are not contextfree

Membership Problem for TwoDimensional General Row Jumping Finite Automata Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200630
Grzegorz Madejski; Andrzej SzepietowskiTwodimensional general row jumping finite automata were recently introduced as an interesting computational model for accepting twodimensional languages. These automata are nondeterministic. They guess an order in which rows of the input array are read and they jump to the next row only after reading all symbols in the previous row. In each row, they choose, also nondeterministically, an order in

Towards RoundOptimal Secure Multiparty Computations: Multikey FHE Without a CRS Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200306
Eunkyung Kim; HyangSook Lee; Jeongeun ParkMultikey fully homomorphic encryption (MFHE) allows homomorphic operations between ciphertexts encrypted under different keys. In applications for secure multiparty computation (MPC) protocols, MFHE can be more advantageous than usual fully homomorphic encryption (FHE) since users do not need to agree with a common public key before the computation when using MFHE. In EUROCRYPT 2016, Mukherjee and

A Unified Method for Private Exponent Attacks on RSA Using Lattices Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200306
Hatem M. Bahig; Dieaa I. Nassr; Ashraf Bhery; Abderrahmane NitajLet (n=pq,e=nβ) be an RSA public key with private exponent d=nδ, where p and q are large primes of the same bit size. At Eurocrypt 96, Coppersmith presented a polynomialtime algorithm for finding small roots of univariate modular equations based on lattice reduction and then succussed to factorize the RSA modulus. Since then, a series of attacks on the key equation ed−kϕ(n)=1 of RSA have been presented

Constrained kCenter Problem on a Convex Polygon Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200306
Manjanna Basappa; Ramesh K. Jallu; Gautam K. DasIn this paper, we consider a restricted covering problem, in which a convex polygon P with n vertices and an integer k are given, the objective is to cover the entire region of P using k congruent disks of minimum radius ropt, centered on the boundary of P. For k≥7 and any 𝜖>0, we propose an (1+7k+7𝜖k+𝜖)factor approximation algorithm for this problem, which runs in O((n+k)(logropt+log⌈1𝜖⌉))

Security of Auditing Protocols Against Subversion Attacks Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200306
Jiaxian Lv; Yi Wang; Jinshu Su; Rongmao Chen; Wenjun WuIn 2013, the revelation of Edward Snowden rekindled cryptographic researchers’ interest in subversion attacks. Since then, many works have been carried out to explore the power of subversion attacks and feasible effective countermeasures as well. In this work, we investigate the study of subversion attacks against cloud auditing protocol, which has been wellknown as useful primitive for secure cloud

CCASecure and Revocable Certificateless Encryption with Ciphertext Evolution Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200306
Yinxia Sun; Futai Zhang; Anmin Fu; Zhe XiaCertificateless cryptosystems have attracted great interests in cryptographic research since its invention. Because compared with traditional public key cryptosystems or identitybased cryptosystems, they could not only simplify the certificate management, but also alleviate the key escrow problem. In certificateless cryptosystems, user revocation is a challenging issue. To address this issue, one

Communication Performance Evaluation of the Locally Twisted Cube Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200306
Yuejuan Han; Lantao You; ChengKuan Lin; Jianxi FanThe topology properties of multiprocessors interconnection networks are important to the performance of high performance computers. The hypercube network Qn has been proved to be one of the most popular interconnection networks. The ndimensional locally twisted cube LTQn is an important variant of Qn. Fault diameter and wide diameter are two communication performance evaluation parameters of a network

Improved Hardness of Maximum Common Subgraph Problems on Labeled Graphs of Bounded Treewidth and Bounded Degree Int. J. Found. Comput. Sci. (IF 0.523) Pub Date : 20200306
Tatsuya Akutsu; Avraham A. Melkman; Takeyuki TamuraWe consider the maximum common connected edge subgraph problem and the maximum common connected induced subgraph problem for simple graphs with labeled vertices (or labeled edges). The former is to find a connected graph with the maximum number of edges that is isomorphic to a subgraph of each of the two input graphs. The latter is to find a common connected induced subgraph with the maximum number