Biblio

The issues of development and legal regulation of cybersecurity in Ukraine are considered. The expediency of further improvement of the regulatory framework, its implementation and development of cybersecurity systems is substantiated. Further development of the theoretical base of cyber defense using spline functions is proposed. The characteristics of network traffic are considered from the point of view of detecting DDoS cyber attacks (SYN-Flood, ICMP-Flood, UDP-Flood) and predicting DDoS cyber-attacks using spline functions. The spline extrapolation method makes it possible to predict DDoS cyber attacks with great accuracy.

Discovering the potential vulnerabilities in software plays a crucial role in ensuring the security of computer system. This paper proposes a method that can assist security auditors with the analysis of source code. When security auditors identify new vulnerabilities, our method can be adopted to make a list of recommendations that may have the same vulnerabilities for the security auditors. Our method relies on graph representation to automatically extract the mode of PDG(program dependence graph, a structure composed of control dependence and data dependence). Besides, it can be applied to the vulnerability extrapolation scenario, thus reducing the amount of audit code. We worked on an open-source vulnerability test set called Juliet. According to the evaluation results, the clustering effect produced is satisfactory, so that the feature vectors extracted by the Graph2Vec model are applied to labeling and supervised learning indicators are adopted to assess the model for its ability to extract features. On a total of 12,000 small data sets, the training score of the model can reach up to 99.2%, and the test score can reach a maximum of 85.2%. Finally, the recommendation effect of our work is verified as satisfactory.

We consider a cloud based multiserver system consisting of a set of replica application servers behind a set of proxy (indirection) servers which interact directly with clients over the Internet. We study a proactive moving-target defense to thwart a DDoS attacker's reconnaissance phase and consequently reduce the attack's impact. The defense is effectively a moving-target (motag) technique in which the proxies dynamically change. The system is evaluated using an AWS prototype of HTTP redirection and by numerical evaluations of an “adversarial” coupon-collector mathematical model, the latter allowing larger-scale extrapolations.

This work presents a highly reliable and tamper-resistant design of Physical Unclonable Function (PUF) exploiting Resistive Random Access Memory (RRAM). The RRAM PUF properties such as uniqueness and reliability are experimentally measured on 1 kb HfO2 based RRAM arrays. Firstly, our experimental results show that selection of the split reference and offset of the split sense amplifier (S/A) significantly affect the uniqueness. More dummy cells are able to generate a more accurate split reference, and relaxing transistor's sizes of the split S/A can reduce the offset, thus achieving better uniqueness. The average inter-Hamming distance (HD) of 40 RRAM PUF instances is 42%. Secondly, we propose using the sum of the read-out currents of multiple RRAM cells for generating one response bit, which statistically minimizes the risk of early retention failure of a single cell. The measurement results show that with 8 cells per bit, 0% intra-HD can maintain more than 50 hours at 150 °C or equivalently 10 years at 69 °C by 1/kT extrapolation. Finally, we propose a layout obfuscation scheme where all the S/A are randomly embedded into the RRAM array to improve the RRAM PUF's resistance against invasive tampering. The RRAM cells are uniformly placed between M4 and M5 across the array. If the adversary attempts to invasively probe the output of the S/A, he has to remove the top-level interconnect and destroy the RRAM cells between the interconnect layers. Therefore, the RRAM PUF has the “self-destructive” feature. The hardware overhead of the proposed design strategies is benchmarked in 64 × 128 RRAM PUF array at 65 nm, while these proposed optimization strategies increase latency, energy and area over a naive implementation, they significantly improve the performance and security.