SIDH hybrid schemes with a classical component based on the discrete logarithm problem over finite field extension

The concept of a hybrid scheme with connection of SIDH and ECDH is nowadays very popular. In hardware implementations it is convenient to use a classical key exchange algorithm, which is based on the same finite field as SIDH. Most frequently used hybrid scheme is SIDH-ECDH. On the other hand, using the same field as in SIDH, one can construct schemes over \Fpn, like Diffie-Hellman or XTR scheme, whose security is based on the discrete logarithm problem. In this paper, idea of such schemes will be presented. The security of schemes, which are based on the discrete logarithm problem over fields \Fp, \Fpd, \Fpc, \Fps and \Fpo, for primes $p$ used in SIDH, will be analyzed. At the end, the propositions of practical applications of these schemes will be presented

(In)security of stream ciphers against quantum annealing attacks on the example of the Grain 128 and Grain 128a ciphers

The security level of a cipher is a key parameter. While general-purpose quantum computers significantly threaten modern symmetric ciphers, other quantum approaches like quantum annealing have been less concerning. However, this paper argues that a quantum annealer specifically designed to attack Grain 128 and Grain 128a ciphers could soon be technologically feasible. Such an annealer would require 5,751 (6,751) qubits and 77,496 (94,708) couplers, with a qubit connectivity of 225 (249). Notably, the forthcoming D-Wave Advantage 2 with Zephyr topology will feature over 7,000 qubits and 60,000 couplers and a qubit connectivity 20. This work also shows that modern stream ciphers like Grain 128 and Grain 128a could be vulnerable to quantum annealing attacks. Although the exact complexity of quantum annealing is unknown, heuristic estimates suggest a $\sqrt{N}$ exponential advantage over simulated annealing for problems with $N$ variables. We detail how to transform algebraic attacks on Grain ciphers into the QUBO problem, making our attack potentially more efficient than classical brute-force methods. We also show that applying our attack to rescaled versions of the Grain cipher, namely Grain $l$ and Grain $la$ versions, where $l$ represents the key size, leads to our attack overtaking both brute-force and Grover\u27s attacks for sufficiently large $l$. This is true, provided that quantum annealing has an exponential advantage over simulated annealing. Specifically, it is sufficient for the time complexity of quantum annealing for problems with $N$ variables to be $e^{N^{\beta}}$ for any $\beta < 1$. Finally, given the general nature of our attack method, all new ciphers should be scrutinized for vulnerability to quantum annealing attacks and at least match the AES cipher in terms of security level

Spatial data quality and uncertainty publication patterns and trends by bibliometric analysis

Using the literature review and quantitative analysis, the research on the quality and uncertainty of spatial data have been compared and analysed according to years of publication, authors, document types, WoS categories, and countries. The paper portrayed the development in the field, studied the state and evolution of the most productive and influential journals, conferences, and research institutions. The results showed that remote sensing, computer science, and geography relate mostly to data imperfection and assessment of its uncertainty. This relation is clearly translated into the most productive journals, and conferences proceedings. The top-ranked countries in this field are United States, China, and the United Kingdom

SIDH Hybrid Schemes with Classical Component Based on the Discrete Logarithm Problem over Finite Field Extension

The concept of a hybrid scheme with connection of SIDH and ECDH is nowadays very popular. In hardware implementations it is convenient to use a classical key exchange algorithm, which is based on the same finite field as SIDH. Most frequently used hybrid scheme is SIDH-ECDH. On the other hand, using the same field as in SIDH, one can construct schemes over Fpn, like Diffie-Hellman or XTR scheme, whose security is based on the discrete logarithm problem. In this paper, idea of such schemes will be presented. The security of schemes, which are based on the discrete logarithm problem over fields Fp; Fp2 ; Fp4 ; Fp6 and Fp8 , for primes p used in SIDH, will be analyzed. At the end, the propositions of practical applications of these schemes will be presented