JOURNAL OF ELECTRONIC AND CYBER DEFENCE
Year:2017 | Volume:5 | Issue:2 (18) |Papers Count:9

The widespread use of the web and development of ICT led to the emergence of a new trade called "database as a service". In this competitive environment، individuals and organizations who find it difficult to manage and maintain their database hire companies that can provide extensive services in the field. Great effort has been made to ensure the integrity of the results of queries on outsourced databases، and a variety of methods have been proposed. However، what is shared between all these methods is that all solutions are offered with high financial considerations by those in the outsourced database business environment. This paper introduces database outsourcing as a business game with four major players: external server، data owner، user and enemy with financial and non-financial interests. It then proceeds to present a way، using the Game Theory، to ensure the integrity of the results of the queries on outsourced databases. This method considers the financial and non-financial interests of the players to be a threat to the integrity of the results of queries، and provides a solution to eliminate this threat. It is believed that this paper can provide useful guidelines for each of the participating parties in business contracts related to database outsourcing، from the service provider to the data owner and the customer.

Ability of intruder tracing، is deterrence to insecurity. One of the methods of intruder tracing is network flow watermark. In this technique، the pattern of network flow is changed، to watermark the special flow of traffic and we can be tracing it in the output boundaries of the network. In this research interval based watermark (IBW) method that ever on TOR anonymous network has not been evaluated، is implement to be practical in the real environment was evaluated on TOR. The analysis results show that this method has the weakness of the border. The proposed method to improve IBW method، with creating a blank space as guard at boundary intervals was used to solve problem in boundary. After implement and evaluate the proposed method، Measurement accuracy based on decoding rates، false positive and false negative. Show proposed method has better performance compared to old method. Also for evaluate stealthness with assume intruder scenario، was used statistic methods: K-S test، entropy test and conditional entropy test to detect watermark. The results show that proposed method in the K-S test and entropy test has acceptable stealthness level.

A random grid is a 2-dimensional array. Each pixel in random grid is either transparent or dark. Darkness and transparency of each pixel are determined by a total random process. This paper introduces a new method for multi-image encryption by random grids. In the proposed method، three binary images are encrypted by only two random grids in such a way that each random grid does not give the attacker any information. Binary images can not be decrypted and reconstructed only when two random grids are accessible. Decryption process is done by XOR operation. The result of implementation of the proposed method showed that reconstructed images have higher visual quality in comparison with previous approaches.

This paper proposes the stability state of micro-grid in islanding mode during occurring cyber-attacks on the power networks. By controlling the rated frequency، it is possible to achieve stability. In order to control rapid frequency، the power balance between production and consumption in every moment must be established; it can be obtained using energy storage system such as batteries with fast dynamic response time. If the battery is designed well، it can lead to the frequency stability of the system by injecting or absorbing reactive power. To contribute more understanding of maximum battery capacity using، an efficient control strategy is designed and simulated via MATLAB/SIMULINK software.

Authentication protocols are tools used to ensure the identity of the parties in cyberspace. If these protocols are compromised، the cyber security is threatened. These threats are of paramount importance in military applications. Recently، in [1] an authentication protocol، called SPRS has been considered and several attacks such as secret disclosure attack، tag impersonation attack and tag traceability attack have been applied on it. In addition، authors of that paper، presented the improved version of the protocol and claimed the improved protocol، unlike its predecessor، is secure against the attacks applied on the predecessor version and also other active and passive attacks. In this paper، we show that unfortunately، the security claims of authors do not hold and the improved protocol is also vulnerable against secret disclosure attack and tag traceability attack. We offer two versions of the secret disclosure attack which are offline and online versions. The basis of the attacks presented in this paper is that given Y=PRNG(X) and PRNG function is a public function and X and Y are 16 bits، performing an exhaustive search to find X as a pre-image of Y with a maximum of 216 off-line evaluations of PRNG function is possible. The offline version of the attack with the complexity of one run of protocol eavesdropping and doing 233 evaluations of PRNG function can disclose 4 secret values of protocol i. e. Ki، Pi، NT and EPCS which are 16 bits and the online version of the attack with the complexity of two times impersonating the reader and doing 217 evaluations of PRNG function can disclose these 4 secret values of protocol. Given these secret disclosure attacks، the improved protocol is not secure against other active and passive attacks as well. In addition، we propose a tag traceability attack to trace a given tag which does not depend on the length of the output of the PRNG function. Given this attack، an adversary can trace a given tag between any two sessions with the reader.

According to the spread of various elections and the need for safety and confidence of the voting process، electronic voting has been of considerable attention. Numerous studies show that the electronic voting system can be proved to the requirements of a voting process. One suitable method for the implementation of electronic voting can be homomorphic encryption. Homomorphic encryption method is an encryption system that is isomorphic to the operation. In this paper، using elliptic curve encryption، a new electronic voting protocol is provided، which can be monitored by all. The system is based on the difficulty of solving discrete logarithm problem on elliptic curve and provides voters and key safety. The proposed protocol was tested for 100 milion voters in a referendum in which the total number of votes was counted in the 30 seconds.

The probability hypothesis density (PHD) filter sequentially computes the first-order multi-target moment for the full multi-target probability density function and dramatically reduces the computational expense of tracking problem. In this paper، we propose an improved implementation of the PHD using the notion of auxiliary particle filter to enhance the effectiveness of the Sequential Monte Carlo (SMC) implementation of the PHD filter. The proposed method differs from traditional SMC implementations because it demonstrates an ability to simultaneously search in an effective way for persistent and newborn targets where the birth intensity is uniform and noninformative. Simulation results indicate that our novel method dramatically improves the accuracy of PHD approximation when compared to traditional SMC implementation methods for the same number of particles.

LBlock is a Lightweight block cipher، with a 64-bit block size and 80-bit key length. Biclique attack is a kind of MITM attack that has recently attracted lots of attention. Biclique cryptanalysis often breaks full version of the cipher on which many other existing attacks do not work. In this paper، firstly، asymmetric biclique is introduced، then by using low data complexity algorithm technique (LDC)، a biclique attack on full round Lightweight block cipher LBlock is presented. The computation and data complexity of this attack are and، respectively. The data complexity is considerably less than the existing cryptanalytic result. The computational complexity remains the same as the previous ones.

LBlock is a Lightweight block cipher, with a 64-bit block size and 80-bit key length. Biclique attack is a kind of MITM attack that has recently attracted lots of attention. Biclique cryptanalysis often breaks full version of the cipher on which many other existing attacks do not work. In this paper, firstly, asymmetric biclique is introduced, then by using low data complexity algorithm technique (LDC), a biclique attack on full round Lightweight block cipher LBlock is presented. The computation and data complexity of this attack are and, respectively. The data complexity is considerably less than the existing cryptanalytic result. The computational complexity remains the same as the previous ones.