Published in Baltic Journal of Law & Politics
Since decentralized organizations such as blockchain are not recognized as legal persons, questions arise regarding the ability to detect anti-competitive practices and their perpetrators. Under certain circumstances, if a competitor is unreasonably refused in access to technology, it may well be interpreted as creating an obstacle to his/her entry...
Published in Cybernetics and Systems Analysis
The role of the blockchain technology in decentralizing modern information systems is discussed. A general model of functioning a blockchain system is analyzed and the idea of constructing a new type of consensus protocols (“proof-of-accuracy” protocols) is proposed that, according to the authors opinion, combines advantages of “proof-of-work” and ...
Published in Cybernetics and Systems Analysis
A new approach to estimating information security of modern information and communication systems is proposed on the basis of the general theory of optimal algorithms. The relation between the quality of information and cryptographic strength of cryptographic and steganographic systems is shown. The choice of the radius of information as the crypto...
Published in Tatra Mountains Mathematical Publications
This paper highlights cryptographic activities from 1540 to about 1680 at the small duchy-Brunswick-Lüneburg in northern Germany, not too far from Hanover (see Fig. 1, p. 2). The analysis shall proceed chronologically and present some relevant examples from the 16th century before focusing on the most important German cryptological author of his ti...
Implementations of cryptosystems are vulnerable to physical attacks, and thus need to be protected against them.Of course, malfunctioning protections are useless.Formal methods help to develop systems while assessing their conformity to a rigorous specification.The first goal of my thesis, and its innovative aspect, is to show that formal methods c...
En cryptographie, l'utilisation de nombres aléatoires est fréquente (graine, token, ...) et une mauvaise génération d'aléa peut compromettre toute la sécurité d'un protocole, comme en témoigne régulièrement l'actualité. Les générateurs de nombres aléatoires à usage cryptographique sont des composants formés de trois modules : la source brute qui pr...
Published in Discrete Mathematics and Applications
The hash algorithms of the MDx family involve cyclic shifts, computation of primitive Boolean functions, and addition of constants. So far, very few works have been published in which the authors attempt to explain the impact that the choice of constants, shifts, and Boolean functions has on the cryptographic properties of the algorithms. G. A. Kar...
Published in Science China Information Sciences
In this paper we present DNA-DBE, a DNA-chip-based dynamic broadcast encryption scheme. In our scheme, new users can join dynamically without modification of other users’ decryption keys. Either the ciphertext or the decryption key is of constant-size. Backward secrecy is achieved in DNA-DBE: if new users join the system dynamically, they will not ...
An encryption relation f Z Z with decryption function f 1 is “group-homomorphic” if, for any suitable plaintexts x1 and x2, x1+x2 = f 1( f (x1)+f (x2)). It is “ring-homomorphic” if furthermore x1x2 = f 1( f (x1) f (x2)); it is “field-homomorphic” if furthermore 1=x1 = f 1( f (1=x1)). Such relations would support oblivious processing of encrypted da...
Flame was an advanced malware, used for espionage, which infected computers running a Microsoft Windows operating system. Once a computer in a local network was infected, Flame could spread to the other computers in the network via Windows Update, disguised as a security patch from Microsoft. Windows Update relies on digital signatures to ensure th...
