The rapidly evolving landscape of network security, particularly in Software Defined Networks (SDNs), presents a critical need for efficient and adaptive DDoS attack detection methods, especially in the face of TCP SYN DDoS attacks. These attacks pose significant threats to network resources and service availability. Current state-of-the-art solutions, predominantly based on Shannon entropy, have inherent limitations, that give equal weightage to all frequency probability. This inherent assumption often leads to inadequate detection in complex and dynamic network environments, where attack patterns are increasingly sophisticated and variable. In this paper, we present a novel framework called SYNTROPY that is designed to detect TCP SYN DDoS attacks in SDN environments. The proposed SYNTROPY framework leverages Rényi entropy to effectively generalize the measurement of uncertainty in the network traffic. Unlike Shannon entropy, Rényi entropy offers the flexibility to adjust sensitivity to varying network conditions and attack patterns, thereby enhancing detection accuracy. It filters benign, flash, and suspicious traffic and employs a min–max threshold to identify attack patterns accurately. Our framework is implemented using the Ryu Controller, thus enabling seamless integration with SDN systems. The experiment is conducted to evaluate the SYNTROPY performance using the CAIDA UCSD DDoS 2007 Attack Dataset. The comparative analysis demonstrates that SYNTROPY performs better across various metrics than state-of-the-art solutions. It includes a 40% reduction in average CPU load, 59% enhancement in average detection time, 13% increase in true positives rate, 34% decrease in false negatives rate, 10% recall improvement, and 8% higher F1-Score. These promising results showcase the potential of SYNTROPY as a robust and effective solution for addressing TCP SYN DDoS attacks in SDNs.

With the continuing growth in various research domains such as Artificial Intelligence (AI), Machine Learning (ML), Big Data Analytics (BDA), and Cloud Computing (CC), the Internet of Things (IoT) has become a popular technology nowadays. It provides a virtual interaction between physical objects and the cyber world over the Internet without human intervention. The IoT devices are embedded with sensors, software, or some other useful technologies for connecting, sharing, and exchanging data with other devices. Among recent technologies impacting human lives, Radio Frequency IDentification (RFID) has become a core identification technology that can be integrated into the IoT environments which connect billions of things or objects. However, an RFID system has two major issues: (i) an adversary can tamper or intercept the sensitive information of the RFID tags, which may cause forgery and privacy problems, and (ii) RFID tags have limited computational power capability which makes it challenging to use current security solutions. To deal with these issues, we propose an anonymous and reliable ultralightweight RFID-enabled authentication scheme (namely AnonR²AS) for IoT systems in a cloud computing environment. AnonR²AS integrates bitwise exclusive-OR, left–right rotations, and ultralightweight half-flip operation, to reduce computational overheads on tag. The AnonR²AS provides stronger security (by preventing several attacks) and improves performance concerning low computational, communication, and storage costs. Also, it preserves information privacy and tags untraceability property by using Vaudenay privacy model. The Scyther simulation tool verification has been performed for its formal security analysis. The performance analysis ensures our AnonR²AS scheme is preferable for low-cost RFID systems.

Outsourcing data users' location data to a cloud server (CS) enables them to obtain kk nearest points of interest. However, data users' privacy concerns hinder the wide-scale use. Several studies have achieved Secure k Nearest Neighbor (SkNN) query, but do not address time-restricted access or result privacy, and randomly partition data items which degrades efficiency. In this article, we propose Time-restricted, verifiable, and efficient Query Processing (TiveQP). TiveQP has three distinguishing features. 1) Expand SkNN: data users can query kk nearest locations open at a specific time. 2) Adopt a stronger threat model: we assume the CS is malicious and propose complementary set (i.e., transform proving 'in' a set to proving 'in' its complementary set) to allow data users to verify results without leaking unqueried data items' information. 3) Improve efficiency: we design a space encoding technique and a pruning strategy to improve efficiency in query processing and result verification. We formally proved the security of TiveQP in the random oracle model. We conducted extensive evaluations over a Yelp dataset to show that TiveQP significantly improves over existing work, e.g., top-10NN query over 100 thousand data items only needs 10 ms to get queried results and 1.4 ms for verification.

Software-defined networking (SDN), enabled by high-performance programmable switches, offers a new avenue to counter cyber attacks. Programmable switches offer the ability to customize and conduct in-depth packet analysis, thus providing efficient and timely responses to DDoS attacks. However, implementing sophisticated DDoS detection may be a challenge in programmable switches because the p4 language does not support floating-point arithmetic, logarithmic functions, or loops. Furthermore, the limited SRAM and TCAM memory on programmable switches makes storing the network connection state difficult. Hence, effective deployment of DDoS detection techniques remains challenging due to these limitations and the rising complexity of the attacks. Many researchers proposed the DDoS detection solution directly on a programmable switch, ignoring the pressing need for a distributed solution. Therefore, this paper presents an innovative, decentralized traffic analysis framework called SPARQ that optimally utilizes the data and control planes. SPARQ is based on Rényi entropy that filters TCP SYN DDoS attacks. It leverages the programming ability of data planes for traffic classification and utilizes the control plane to calculate the metrics and acyclic redundancy checks within the traffic. Moreover, SPARQ uses quartile ranges to track packet inter-arrival time so that abnormal traffic patterns can be identified. We implement SPARQ in a BMv2 switch using the p4runtime controller, enabling seamless integration with SDN systems. We compare the performance of SPARQ with state-of-the-art solutions using the CAIDA dataset. The comparative analysis demonstrates that SPARQ provides a 20.59% reduction in CPU load, an average detection time shorter than 88%, and a 17.8% improvement in true positive rate (TPR).