Yazar "Das, Resul" seçeneğine göre listele

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    An Android Application to Secure Text Messages
    (IEEE, 2017) Demirol, Doygun; Das, Resul; Tuna, Gurkan
    For mobile phone users, short message service (SMS) is the most commonly used text-based communication type on mobile devices. Users can interact with other users and services via SMS. For example, users can send private messages, use information services, apply for a job advertisement, conduct bank transactions, and so on. Users should be very careful when using SMS. During the sending of SMS, the message content should be aware that it can be captured and act accordingly. Based on these findings, the elderly, called as Silent Generation which represents 70 years or older adults, are text messaging much more than they did in the past. Therefore, they need solutions which are both simple and secure enough if there is a need to send sensitive information via SMS. In this study, we propose and develop an android application to secure text messages. The application has a simple and easy-to-use graphical user interface but provides significant security.
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    Common Network Attack Types and Defense Mechanisms
    (IEEE, 2015) Das, Resul; Karabade, Abubakar; Tuna, Gurkan
    For every organization having a well secured network is the primary requirement to reach their goals. A network is said to be secure if it can protect itself from sophisticated attacks. Due to the rapid increase in the number of network users, security becomes the main challenge in the area of network field. Most security related threats target the layers of the OSI reference model. Sophisticated attack types such as Distributed Denial of Service (DDoS), Man-in-the-Middle and IP spoofing attacks are used to attack these layers. In this paper, we analyze most of the attack types that cause serious problems in computer networks and defense techniques to stop or prevent these attacks.
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    Cryptolog: A new approach to provide log security for digital forensics
    (Istanbul Univ, Fac Engineering, 2017) Baykara, Muhammet; Das, Resul; Tuna, Gurkan
    As security vulnerabilities generated by the developments in information and communication technologies as well as emerging technologies can lead to severe loss in terms of individual and institutional aspects, the importance of information security has been increasing in recent years. Nowadays, digital information is considered as an important asset which must be appropriately evaluated and protected against all forms of unauthorized access, use, disclosure, modification, destruction, or denial. Since information security is more prominent and more important now than ever before, this growing awareness of digital information security has led societies to develop innovative ways of protecting their sensitive information. On the other hand, in today's digital world, keeping sensitive information secure is not as easy as it was in the past. In this regard, it is obvious that for all types of institutions there is a need for security software which provides the necessary security measures and policies for the protection and retrieval of sensitive digital information. To ensure information security, security software must have the ability to make logging of certain events. Through log files, some analysis can be performed to find out what kind of attacks were done by which users and when. In this respect, this study proposes a novel approach of recording traffic flow on the log files stored on a server to determine the changes made by unauthorized people/users on the log records, and this way ensures the security of the log records and contributes to digital forensics processes in terms of accuracy, integrity and confidentiality of the log records.
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    The Impact of Increasing Number of Nodes on the Performance of Well-Known Trust and Reputation Models for Wireless Sensor Networks
    (Istanbul Univ-Cerrahapasa, 2020) Tuna, Gurkan; Das, Resul
    In recent years, several trust and reputation management models have been proposed to address the security issues of wireless sensor networks. In wireless sensor networks, trust and reputation management systems basically allow sensor nodes to make their own opinion about how trustworthy other nodes are so that a higher number of successful transactions can be obtained and the probability of being defrauded reduced. To assess the performance of trust and reputation management systems a number of performance metrics were proposed. In this study, with the aim of finding out the most suitable trust and reputation model when the number of sensor nodes involved in a wireless sensor network has been increased, the performance of EigenTrust, Linguistic Fuzzy Trust Mechanism, PeerTrust and PowerTrust is evaluated in terms of accuracy rate and path length. The reason for focusing on this is that if a trust and reputation model is able to achieve the same accuracy rate and path length performance without any performance degradation when more sensor nodes are involved in the network, it can be considered as scalable. The results of our simulation studies prove that compared to the other models, Linguistic Fuzzy Trust Mechanism provides higher accuracy and less path length scores and is more suitable for large-scale deployments of wireless sensor networks.
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    A novel approach to steganography: Enhanced least significant bit substitution algorithm integrated with self-determining encryption feature
    (C R L Publishing Ltd, 2019) Das, Resul; Baykara, Muhammet; Tuna, Gurkan
    One of the most well-known and used algorithms for Steganography is Least Significant Bit (LSB) substitution. Although LSB has several advantages such as simplicity, efficiency, and easy-to-do implementation, it has some distinct disadvantages such as it openness to miscellaneous attacks. In this study, we aim to improve the traditional LSB algorithm by eliminating its main disadvantage, being easy to detect, and this way propose an enhanced LSB algorithm called E-LSB. We mainly aim to minimize differences which are due to encryption and image hiding steps in LSB algorithm and make it more difficult to notice that some text has been hidden in the original cover image. As most of the researchers and practitioners in security field argue, stenographic techniques alone are not sufficient for protecting sensitive information and thus must be used together with encryption algorithms. Therefore, the proposed approach integrates E-LSB with an encryption algorithm. E-LSB does not modify the file size and allows the flexibility of choosing one of well-known encryption algorithms including RSA, AES and CAESAR, but others can be implemented in it. With a set of experiments, the proposed approach is compared with the traditional LSB based embedding approach, and its efficiency and usability is analyzed. A set of performance evaluations realized with the developed software tool based on E-LSB algorithm show that E-LSB is better than the traditional LSB algorithm from security point of view.
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    Packet Tracing and Analysis of Network Cameras with Wireshark
    (IEEE, 2017) Das, Resul; Tuna, Gurkan
    Although people think that their identity is not revealed on the internet, the confidentiality and protection of personal information on unreliable networks such as the internet is an important question. In this study, a sample application on network packet tracing and analysis of network cameras with Wireshark program is realized to show how partial access to personal information and location information is obtained. As it is shown, network packets coming from/sent to IP cameras can be traced and analysed with Wireshark program. Moreover, it is shown that the location information can easily be obtained. This confirms that personal information can be captured and used for illegal purposes if the data is transferred over unreliable networks.
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    A Simple Logging System for Safe Internet Use
    (IEEE, 2017) Demirol, Doygun; Tuna, Gurkan; Das, Resul
    Although the Internet offers numerous advantages, it raises many information security risks, especially against young people and children, who are today amongst the largest user groups of mobile and online technologies all around the world. Therefore, to empower and protect Internet users, it is necessary to develop proper strategies and tools to encapsulate their needs, and identify and prevent all types of the information security risks that may arise during the use of the Internet. In this study, a tracking system to ensure the safe use of the Internet is proposed. Considering the distribution of its potential users, the system has an easy-to-use graphical user interface. By recognizing dangerous web sites and IP addresses, the proposed system blocks access to those sites and this way provides reliable Internet access to its users. During the Internet access, it analyzes accessed IP addresses and port numbers in terms of access type and time and informs the user of the corresponding port numbers which must be closed for safe Internet access. Moreover, by continuously checking the host redirection file of the computer it runs on, it identifies redirections from web addresses to specific IP addresses and this way provides protection against phishing attacks which are becoming one of the most common Internet threats. Although the proposed system is a simple application since it is an open source, freeware application designed for children, it can be improved to consider more sophisticated attack types.