Checking Sequence Research Articles

A Combined Technique of SC + MPC + APC to Achieve Higher Error Correction Probability and Throughput Over APC and MPC Techniques in a Wireless Network

In this paper, we present the combined techniques of Selection Combining (SC), Modified Packet Combining (MPC) and Aggressive Packet Combining (APC) for higher probability of packet error correction and packet throughput in three branches diversity system (multi-path) over conventional MPC and APC techniques. The three copies of the same packet are used to transmit from transmitter (Tx) to receiver (Rx) in three paths. Like in conventional SC technique, the Rx checks all the received copies individually from three paths whether the received copies are correct or not using frame checking sequences. If any one of the received copies is obtained, the correct copy then it will discard the remaining copies and request for next packet; otherwise the received erroneous copies will be combined. The combined erroneous copies perform ‘r’ number of pair-wise XORed after the erroneous copies are performed bit converted in MPC technique. If ‘r’ pair-wise XOR operations fail to recover the original copy, then APC technique implements with the converted bit stream. Thus, the simulation results using MATLAB obtain better performance in terms of probability of packet error correction and packet throughput over conventional MPC and APC schemes.

Improvement of the Semi-quantum Secret Sharing Protocol of Specific Bits

Recently, Gao et al. (Int. J. Theor. Phys. 56(8), 2512–2520 (2017)) pointed out that Yin and Fu’s semi-quantum secret sharing (SQSS) protocol of specific bits is not semi-quantum and suggested an improved one. In this paper, an improvement for Gao et al.’s protocol is proposed. Different from Gao et al.’s protocol, the proposed improved protocol prepares single photons to form both the message sequences and the checking sequences. As a result, compared with Gao et al.’s protocol, the improved protocol is much easier to realize in practice, due to no use of quantum entangled states and their measurements, and has higher quantum efficiency.

Research on Fault Diagnosis Method of Tunnel Inspection Robot Based on T−S Fuzzy FTA

Aiming at the intelligent fault diagnosis of tunnel inspection robot, the T-S fuzzy fault tree method was proposed to build the intelligent diagnosis system. Taking positioning system of the robot as an example, the T-S fuzzy FTA model of the system was established. And the T-S importance of each component and fault checking sequence were calculated using the T-S fuzzy gate rule. The example analysis results show that, the method improves the accuracy and practicability of fault diagnosis of the robot system.

FSM inference and checking sequence construction are two sides of the same coin

The paper focuses on the problems of passive and active FSM inference as well as checking sequence generation. We consider the setting where an FSM cannot be reset so that its inference is constrained to a single trace either given a priori in a passive inference scenario or to be constructed in an active inference scenario or aiming at obtaining checking sequence for a given FSM. In each of the last two cases, the expected result is a trace representing a checking sequence for an inferred machine, if it was not given. We demonstrate that this can be achieved by a repetitive use of a procedure that infers an FSM from a given trace (identifying a minimal machine consistent with a trace) avoiding equivalent conjectures. We thus show that FSM inference and checking sequence construction are two sides of the same coin. Following an existing approach of constructing conjectures by SAT solving, we elaborate first such a procedure and then based on it the methods for obtaining checking sequence for a given FSM and inferring a machine from a black box. The novelty of our approach is that it does not use any state identification facilities. We demonstrate that the proposed approach can also be constrained to find a solution in a subset of FSMs represented by a nondeterministic mutation machine. Experiments with a prototype implementation of the developed approach using an existing SAT solver indicate that it scales for FSMs with up to a dozen of states and requires relatively short sequences to identify a black box machine.

Deterministic Quantum Secure Direct Communication and Authentication Protocol Based on W‐Class State

A Quantum secure direct communication (QSDC) and authentication protocol based on the W-class state is presented to enhance the efficiency of eavesdropping detection. In this protocol, the W-class state is used to transmission the checking sequence and detect eavesdroppers. In the security analysis, the method of entropy theory is introduced, and two detection strategies are compared quantitatively by using the constraint between the information that eavesdroppers can obtain and a normalized difference parameter is introduced. To obtain the same amount of information, the eavesdropper must face a higher detection probability in the proposed protocol than in the comparison. The security of the proposed protocol is also discussed. The analysis results indicate that the proposed protocol is more secure, but it must send more particles.

Методи синтезу легкотестованих цифрових пристроїв і систем

The analysis of previously published works in the field of experiments with automates shows that the methods of constructing of diagnostic experiments with automates, having a distinctive sequence are studied in majority of cases. The known experiments with initial automates are based on the assumption of correctness of automate setting to the initial state. Therefore, methods of construction of complete checking sequences using the distinctive, characteristic and synchronizing sequences, which also verify the correctness of the initial setting are proposed in this article for the class of initial automates. The purpose of creating of method of transformation of automate diagram of discrete devices by introduction of additional input symbol and automate state coding, which provides for this symbol transition function of automate diagram of shift register is set in the article. As well creating of method of finding of Hamiltonian cycles in transition graph shift register with given number of states, which create counter binary sequences that formed by shift register with nonlinear feedback is the purpose of the research.

Effective algorithms for constructing minimum cost adaptive distinguishing sequences

Context: Given a Finite State Machine (FSM), a checking sequence is a test sequence that determines whether the system under test is correct as long as certain standard assumptions hold. Many checking sequence generation methods use an adaptive distinguishing sequence (ADS), which is an experiment that distinguishes the states of the specification machine. Furthermore, it has been shown that the use of shorter ADSs yields shorter checking sequences. It is also known, on the other hand, that constructing a minimum cost ADS is an NP-hard problem and it is NP-hard to approximate. This motivates studying and investigating effective ADS construction methods.Objective:The main objective of this paper is to suggest new methods that can compute compact ADSs to be used in the construction of checking sequences.Method:We briefly present the existing ADS construction algorithms. We then propose generalizations of these approaches with a set of heuristics. We also conduct experiments to compare the size of the resultant ADSs and the length of the checking sequences constructed using these ADSs.Results:The results indicate that when the ADSs are constructed with the proposed methods, the length of the checking sequences may reduce up to 54% (40% on the average).Conclusions:In this paper, we present the state of the art ADS construction methods for FSMs and we propose generalizations of these methods. We show that our methods are effective in terms of computation time and ADS quality.

К синтезу адаптивных проверяющих последовательностей для недетерминированных автоматов

К синтезу адаптивных проверяющих последовательностей для недетерминированных автоматов

Quantum Secure Direct Communication Using Checking Sequence Coded

The checking sequence of the schemes of quantum secure direct communication based on a secret transmitting order of particles is only checked for security, which is limited quantum resource and is not made the best. The checking sequence is only checked for security by analyzing quantum secure direct communication proposed before. The novel protocol codes the checking sequence which is added the certain meaning in addition to security checks, named the protocol of the sub-step secret transmitting order of particles using the checking sequence coded. Through analysis by synthesis the novel protocol has higher security and reliability.

Reduced checking sequences using unreliable reset

The length of a checking sequence (CS) generated from a deterministic, minimal, and completely specified finite state machine model M of a system under test which does not have a reliable reset feature, is exponential when M does not have a distinguishing sequence. This is due to the exponential length locating sequences that need to be used in such a CS. In this work, we propose a method to decrease the number of locating sequences used in CS, by first verifying the reset input r and then using r as a reliable reset. When such a reset input is not available, a synchronizing sequence can be used as a compound reset input, which makes the proposed method applicable to a wide range of systems.

Efficient Security Authentication Protocol in Wireless Sensor Networks

Wireless sensor networks consist of a network of autonomous sensors that can reconfigure themselves so as to sense the environment in the most significant manner. However, a significant challenge in the practical application of these networks exists in credible authentication and network security. This paper proposes a secure authentication protocol which is considered as a pro-active method, where a user is strongly verified before accessing the data, it is the modified Adhoc On-Demand Distance vector (AODV) Routing protocol that provides many security principles to the user such as checking sequence number, IP address and threshold values. The performance of proposed algorithm is compared with the existing alogorithm based on the following parameters such as Throughput, End to End delay and packet delivery ratio. The results shows that the proposed protocol possesses many advantages against the popular black hole attack. This work has been carried out using NS2 software and the result obtained testifies the effectiveness of the proposed protocol. Keyword: Authentication protocol, AES security, AODV routing protocol, Black hole attack, Wireless sensor network (WSN).

On the global optimization of checking sequences for finite state machine implementations

A checking sequence for a given domain of deterministic finite state machine implementations is an input sequence for which exactly the non-faulty members of the domain produce a non-faulty response. In the paper, we reconsider a popular family of methods which construct a checking sequence by performing its digraph-based global optimization. Recently, it was demonstrated that many of the methods are unsafe. As a remedy, a simple, but sufficient set of additional constraints on the structure of the employed digraph was introduced. In this paper, we show that the constraints sometimes ban also some of those originally considered checking sequence candidates which are sound. To safely restore the original power of the checking sequence construction approach, we perform its thorough re-engineering. This results in a very transparent and flexible generic method from which various methods of practical interest, both new ones and analogues of the traditional ones, can be derived simply by specialization.

Синтез проверяющих последовательностей для недетерминированных автоматов относительно редукции

Most FSM based methods for test derivation are developed for initialized Finite State Machines (FSM) and the latter means that a reliable reset is assumed in an implementation under test in order to glue test sequences together. If the reset is rather expensive then the number of test sequences has to be reduced and when it is reduced to a single sequence, this sequence is called a checking sequence. In this paper, a methods is proposed for deriving an adaptive checking sequence when the specification FSM is nondeterministic and the conformance relation is the reduction relation. The latter means that the behavior of a conforming implementation should be contained in the behavior of the specification. A method returns an adaptive checking sequence that detects each nonconforming implementation that has not more states than the specification FSM under the conditions that the specification has a distinguishing sequence and a deterministic strongly connected submachine. These conditions can be weakened for the case when the specification has a distinguishing test case and each state of the specification is definitely reachable from another state. The testing process is adaptive, i.e., the next input is determined based on the outputs produced for the previous inputs. Such adaptive distinguishing sequences can be shorter than preset checking sequences.

One-way deterministic secure quantum communication protocol based on single photons

One-way deterministic secure quantum communication protocol based on single photons is proposed in this paper, in which the XOR operation by bits of the information sequence and random sequence is performed and the checking sequence is inserted before the sender’s coding operation. When the photons arrive at the receiver, they are delayed at the receiver, and the sender then publishes the coding basis, so the photons can be measured in the correct basis. Then the two parties estimate the security of the quantum channel by the checking bits. When the channel is secure the sender publishes the random bits where the receiver has results, and the information sequence can be recovered by the receiver. Even the channel is not secure, what the eavesdropper gets is the random sending sequence, the information sequence is still secure. This protocol has the advantages of higher transmission efficiency and easier implementation compared with the two-way communication.

Generating a checking sequence with a minimum number of reset transitions

Given a finite state machine M, a checking sequence is an input sequence that is guaranteed to lead to a failure if the implementation under test is faulty and has no more states than M. There has been much interest in the automated generation of a short checking sequence from a finite state machine. However, such sequences can contain reset transitions whose use can adversely affect both the cost of applying the checking sequence and the effectiveness of the checking sequence. Thus, we sometimes want a checking sequence with a minimum number of reset transitions rather than a shortest checking sequence. This paper describes a new algorithm for generating a checking sequence, based on a distinguishing sequence, that minimises the number of reset transitions used.

Lower bounds on lengths of checking sequences

Abstract Lower bounds on the lengths of checking sequences constructed for testing from Finite State Machine-based specifications are established. These bounds consider the case where a distinguishing sequence is used in forming state recognition and transition verification subsequences and identify the effects of overlapping among such subsequences. Empirical results show that the existing methods for construction of checking sequences provide checking sequences with lengths that are within acceptable distance to these lower bounds.

Exploring alternatives for transition verification

When an implementation under test (IUT) is state-based, and its expected abstract behavior is given in terms of a finite state machine (FSM), a checking sequence generated from a specification FSM and applied to an IUT for testing can provide us with high-level confidence in the correct functional behavior of our implementation. One of the issues here is to generate efficient checking sequences in terms of their lengths. As a major characteristics, a checking sequence must contain all β-sequences for transition verification. In this paper, we discuss the possibility of reducing the lengths of checking sequences by making use of the invertible transitions in the specification FSM to increase the choice of β-sequences to be considered for checking sequence generation. We present a sufficient condition for adopting alternative β-sequences and illustrate typical ways of incorporating these alternative β-sequences into existing methods for checking sequence generation to reduce the lengths. Compared to the direct use of three existing methods, our experiments show that most of the time the saving gained by adopting alternative β-sequences falls in the range of 10–40%.

Correction to "Reduced Length Checking Sequences" [Sep 02 93-99

This paper describes corrections to a previous paper, Reduced Length Checking Sequences, that appeared in IEEE Transactions on Computers in 2002 (51 9, pp.1111-1117).

Checking sequences for distributed test architectures

Controllability and observability problems may manifest themselves during the application of a checking sequence in a test architecture where there are multiple remote testers. These problems often require the use of external coordination message exchanges among testers during testing. However, the use of coordination messages requires the existence of an external network that can increase the cost of testing and can be difficult to implement. In addition, the use of coordination messages introduces delays and this can cause problems where there are timing constraints. Thus, sometimes it is desired to construct a checking sequence from the specification of the system under test that will be free from controllability and observability problems without requiring the use of external coordination message exchanges. This paper gives conditions under which it is possible to produce such a checking sequence, using multiple distinguishing sequences, and an algorithm that achieves this.

Optimizing the length of checking sequences

A checking sequence, generated from a finite state machine, is a test sequence that is guaranteed to lead to a failure if the system under test is faulty and has no more states than the specification. The problem of generating a checking sequence for a finite state machine M is simplified if M has a distinguishing sequence: an input sequence D~ with the property that the output sequence produced by M in response to D is different for the different states of M. Previous work has shown that, where a distinguishing sequence is known, an efficient checking sequence can be produced from the elements of a set A of sequences that verify the distinguishing sequence used and the elements of a set /spl gamma/ of subsequences that test the individual transitions by following each transition t by the distinguishing sequence that verifies the final state of t. In this previous work, A is a predefined set and /spl gamma/ is defined in terms of A. The checking sequence is produced by connecting the elements of /spl gamma/ and A to form a single sequence, using a predefined acyclic set E/sub c/ of transitions. An optimization algorithm is used in order to produce the shortest such checking sequence that can be generated on the basis of the given A and E/sub c/. However, this previous work did not state how the sets A and E/sub c/ should be chosen. This paper investigates the problem of finding appropriate A and E/sub c/ to be used in checking sequence generation. We show how a set A may be chosen so that it minimizes the sum of the lengths of the sequences to be combined. Further, we show that the optimization step, in the checking sequence generation algorithm, may be adapted so that it generates the optimal E/sub c/. Experiments are used to evaluate the proposed method.