A Survey of Security Issues in Cognitive Radio Networks

In the last decade,cognitive radio(CR) has emerged as a major next generation wireless networking technology,which is the most promising candidate solution to solve the spectrum scarcity and improve the spectrum utilization.However,there exist enormous challenges for the open and random access environment of CRNs,where the unlicensed secondary users(SUs) can use the channels that are not currently used by the licensed primary users(PUs) via spectrum-sensing technology.Because of this access method,some malicious users may access the cognitive network arbitrarily and launch some special attacks,such as primary user emulation attack,falsifying data or denial of service attack,which will cause serious damage to the cognitive radio network.In addition to the specifi c security threats of cognitive network,CRNs also face up to the conventional security threats,such as eavesdropping,tampering,imitation,forgery,and noncooperation etc..Hence,Cognitive radio networks have much more risks than traditional wireless networks with its special network model.In this paper,we considered the security threats from passive and active attacks.Firstly,the PHY layer security is presented in the view of passive attacks,and it is a compelling idea of using the physical properties of the radio channel to help provide secure wireless communications.Moreover,malicious user detection is introduced in the view of active attacks by means of the signal detection techniques to decrease the interference and the probabilities of false alarm and missed detection.Finally,we discuss the general countermeasures of security threats in three phases.In particular,we discuss the far reaching effect of defensive strategy against attacks in CRNs.

Captcha-Based Honey Net Model against Malicious Codes

The rate of passive and active attacks has been on the increase lately affecting both individuals and institutions. Even when internal control procedures are in place, malicious codes from intruders into the network have left so much to be desired. As a result, many Chief Information Security Officers have grown grey hair because of their inability to effectively handle attacks from various ends. Various attempts and technologies have been made in the time past with a measure of success. Intrusion Detection Software (IDS), Intrusion Prevention Software, firewall, honey pots and honey nets have been deployed and with great respite from losses arising from cyber-attacks. Cyber security is the duty of everyone and all must see it as such. As tiers of government and law enforcement agents are doing their best, everybody must be seen to play their parts. Fraudsters have also not seemed to be tired of seeking vulnerabilities to exploit. Then, cyber security experts should not let off their guards but make efforts to harden their security. A way of doing is to intelligently provide a solution that has the capability of detecting and proactively hardening security. This paper proposes a honey net model that is captcha-based and capable of extracting details from hackers with a view to building a robust defense against black hat attackers. This research was able to prevent the botnet with the use of captcha and also redirect suspected traffic to the honeynet which was then captured for the purpose of improving the security of the network. The result showed that any bandwidth greater than the set threshold was not allowed to go into the network but redirected to honeynet where details were logged. Also, with a threshold of 100 mbs, inbound traffic of higher bandwidth such as 110 mbs and 150 mbs was denied access thereby giving 100% detection rate.

Implementation of Positive Operator-Valued Measure in Passive Faraday Mirror Attack

Passive Faraday-mirror(PFM) attack is based on imperfect Faraday mirrors in practical quantum cryptography systems and a set of three-dimensional Positive Operator-Valued Measure(POVM) operators plays an important role in this attack.In this paper,we propose a simple scheme to implement the POVM in PFM attack on an FaradayMichelson quantum cryptography system.Since the POVM can not be implemented directly with previous methods,in this scheme it needs to expand the states sent by Alice and the POVM operators in the attack into four-dimensional Hilbert space first,without changing the attacking effect by calculation.Based on the methods proposed by Ahnert and Payne,the linear-optical setup for implementing the POVM operators is derived.At last,the complete setup for realizing the PFM attack is presented with all parameters.Furthermore,our scheme can also be applied to realize PFM attack on a plug-and-play system by changing the parameters in the setup.

Information Security Protocol Based System Identification with Binary-Valued Observations

Traditional control does not pay much attention to information security problems in system identification enough, which are important in practical applications. This paper focuses on the security problem of input information in a class of system identification problems with noise and binary-valued observations, presents a cryptography based security protocol, and improves it in the range of allowed errors. During solving the identification problem, the improved security protocol can ensure that the input information is not leaked, and thus, can deal with passive attacks effectively. Besides, a quantitative relationship among the input information, the public key in encryption and the number of partieipailts in the improved protocol is shown. Finally, the simulation results show that, the identification algorithm can still achieve the estimation accuracy by adding the improved security protocol. However, compared with the original identification algorithm, the time complexity of the algorithm with the improved security protocol increases.

Cryptanalysis and improvement of several quantum private comparison protocols

Recently, Wu et al(2019 Int. J. Theor. Phys. 58 1854) found a serious information leakage problem in Ye and Ji’s quantum private comparison protocol(2017 Int. J. Theor. Phys. 561517), that is, a malicious participant can steal another’s secret data without being detected through an active attack means. In this paper, we show that Wu et al’s active attack is also effective for several other existing protocols, including the ones proposed by Ji et al and Zha et al(2016 Commun. Theor. Phys. 65 711;2018 Int. J. Theor. Phys. 57 3874). In addition,we propose what a passive attack means, which is different from Wu et al’s active attack in that the malicious participant can easily steal another’s secret data only by using his own secret data after finishing the protocol, instead of stealing the data by forging identities when executing the protocol. Furthermore, we find that several other existing quantum private comparison protocols also have such an information leakage problem. In response to the problem, we propose a simple solution, which is more efficient than the ones proposed by Wu et al, because it does not consume additional classical and quantum resources.