Institute of Mathematics AS CR, v. v. i.
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Method for quantitative risk assessment of cyber-physical systems based on vulnerability analysis
Get PDFsummary:Cyber-physical system protection against cyber-attacks is a serious problem that requires methods for assessing the cyber security risks. This paper proposes a quantitative metric to evaluate the risks of cyber-physical systems using the fuzzy Sugeno integral. The simulated attack graph, consisting of vulnerable system components, allows for obtaining various parameters for assessing the risks of attack paths characterizing the elements in the cyber and physical environment and are combined into a single quantitative assessment. Experiments are performed on a threat model using the example of a cyber-physical system for wind energy generation. The model integrates a cyber-physical network's topology and vulnerabilities, proving the proposed method's effectiveness in ensuring cyber resilience
The Czech Digital Mathematics Library Has Been Serving the Public for 15 Years
No full textsummary:Článek je věnován úspěšnému projektu České digitální matematické knihovny. Uvádí, co projektu předcházelo, a~připomíná vývoj publikování odborné matematické literatury. Popisuje, jak tvorba digitální knihovny probíhá a~jaký je její současný stav
A cryptography using lifting scheme integer wavelet transform over min-max-plus algebra
Get PDFsummary:We propose a cryptographic algorithm utilizing integer wavelet transform via a lifting scheme. In this research, we construct some predict and update operators within the lifting scheme of wavelet transforms employing operations in min-max-plus algebra, termed as lifting scheme integer wavelet transform over min-max-plus algebra (MMPLS-IWavelet). The analysis and synthesis process on MMPLS-IWavelet is implemented for both encryption and decryption processes. The encryption key comprises a sequence of positive integers, where the first element specifies MMPLS-IWavelet type and subsequent elements indicate the levels of each executed transformation. The decryption key involves three components: the original encryption key, a binary encoding of the analyzed signal, and a sequence of non-negative integer representing the length of coefficient signals from the approximation and detail signals. We present a rigorous analysis confirming the correctness of the proposed cryptographic scheme, and evaluate its performance based on various metrics such as correlation value between plaintext and ciphertext, encryption quality, computation time, key sensitivity, entropy analysis, and key space analysis. We also analyze the computational costs of the encryption and decryption processes. The experimental results demonstrate that the proposed algorithms empirically yield satisfactory performance, exhibiting a near zero correlation between plaintext and ciphertext for most of test data, high encryption quality (over 80 percent), substantial key sensitivity, the large key space, and greater randomness in ciphertext compare to plaintext. The algorithm is efficient in terms of computational time and has linear complexity with respect to the number of input characters. The vast key space makes it highly impractical for brute-force approaches to find the decryption key directly