Browsing by Author "Khan, Burhan Ul Islam"

The security problems in Mobile Adhoc Networks (MANETs) are being constant topic of interest and drawn attention of research community from past decade, where massive study has already been presented for addressing the same. One of the precarious problems encountered in MANET is that of identifying the malicious nodes. The identification and later mitigation of the same becomes immensely difficult task especially when Selfish / Erroneous nodes exist along with normal Collaborative nodes in the Regular camp. The presence of selfish nodes is potentially harmful as similar behaviour can be imitated by malicious nodes which are the point of concern of many security aspects. While performing the preliminary study of the proposed system, it was known that large amount of previous study has emphasized on usage of cryptographic protocols to secure MANET, where implementation becomes a big question mark and challenges time and space complexity of those sophisticated algorithm. While reviewing some more techniques on security system in MANET, it was found that game theory has also prime contribution in past few years due to potential accuracy in its probabilistic approach and computational efficiency. Therefore, the proposed system accentuates the use of game theory and probability theory considering selfish nodes in the regular node camp while modeling the Regular versus Malicious node game and thereby enhancing the prior mathematical schema of strategical decision making to accommodate for the same. The study performs statistical analysis and presents a mathematical model to mimic the multi-stage game between regular and malicious node using Game Theory. The framework effectively represent the various unpredictable actions of node cooperation, node declination, node attacks , as well as node reporting that can model the strategic profiling of various mobile nodes. Understanding the patterns and then deploying the algorithms in security products can reduce intrusion to a greater extend. The simulation has been conducted in Matlab for monitoring the trends of pure strategy, mixed strategy, and PBE strategy adoption to visualize the behavioral pattern of mobile nodes. The outcome of the study shows significant enhancement in reporting actions of regular node thus considerable reduce down vulnerability scenario in MANET. The study lays emphasis on Perfect Bayesian Equilibrium (PBE) strategy which forms as the basis of all the result analysis. The enhancement was found in terms of 62.67 % lesser false positives which favors higher overall network utility (modeled as utility of regular nodes in the game) with Selfish / Erroneous nodes existing in the network when collating the proposed schema with prior work.

Numerous applications are widespread on Internet and mobile communications that transfer personal information and money. Foolproof user authentication becomes imperative in such applications for confirming customer legitimacy. One pragmatic solution for user authentication is that of employing One Time Password (OTP) with validity for a single transaction or session. Two contextually active user authentication models for internet banking in Malaysia include i.) Receiving OTP over the phone via an SMS, ii.) Generating the OTP over a dedicated hardware token provided by the Bank. SMS OTPs are the most common means used for access control over different online applications, especially Internet banking. However, with this setup, the password generated remains afloat in an unsecured cellular network, thereby increasing the probability of security breaches. Additionally, users need to maintain two active communication channels (Cellular & Internet) with the Authentication Server for proving legitimacy. Other inherent problems include delay-in-delivery, coverage areas/unavailability of service, roaming restrictions, dependency on government regulations, etc. Usage of dedicated hardware for OTP generation is also quite popular. Some of these tokens can even generate OTPs asynchronously. However, this setup brings forth additional logistical and administrative burdens for the customers. Besides, users availing multiple service providers need to maintain distinct tokens for each service. The research focussed on developing a standalone authentication framework for generating unique OTPs from trusted handheld devices using a hybrid approach (based on time as well as challenge response strategy), complying with the degree of authentication assertion essential for Internet-banking applications. The prime intent is to eradicate dependence over additional cellular communication channels and eliminate the use of extra hardware tokens for generating/receiving OTPs by Internet banking clients without compromising the security traits of the system. The proposed authentication framework generates time-based dynamic authentication components (OTPs) in an offline manner (without requiring any cellular or internet connectivity) on user's smartphones by invoking possession, knowledge, and inherence factors of legitimate users. This is achieved by asynchronously operating secure random challenge formations as hash counters upon dynamic seeds, comprising of varying current timestamps, distinct device and identity profiles. It drastically reduces the operational costs, improves upon security, scalability, and convenience factors. Additionally, the system has been equipped to generate OTPs as three Bahasa Malaysia dictionary words as the usage of native language words during verification could help clients to feel more confident and secure compared to making foreign-language entries. The system has been implemented and examined for leading mobile/desktop platforms to ascertain its technical adoptability. The results of performance metrics obtained employing the confusion matrix with Accuracy = 98.55%, Error rate = 1.45%, Specificity = 100%, Alarm rate = 0%, Recall = 98.40% and Precision = 100% validate the authentication robustness. The generation and extraction aspects of the hybrid OTP design are comparatively analysed against prior asynchronous/synchronous OTP generation schemes. Furthermore, the authentication framework is comparatively comprehensively parsed for its ability to thwart common authentication attacks over the Internet.