Implementing Symmetric Cryptography Using Sequence of Semi-Bent Functions

Symmetric cryptography is a cornerstone of everyday digital security, where two parties must share a common key to communicate. The most common primitives in symmetric cryptography are stream ciphers and block ciphers that guarantee confidentiality of communications and hash functions for integrity. Thus, for securing our everyday life communication, it is necessary to be convinced by the security level provided by all the symmetric-key cryptographic primitives. The most important part of a stream cipher is the key stream generator, which provides the overall security for stream ciphers. Nonlinear Boolean functions were preferred for a long time to construct the key stream generator. In order to resist several known attacks, many requirements have been proposed on the Boolean functions. Attacks against the cryptosystems have forced deep research on Boolean function to allow us a more secure encryption. In this work we describe all main requirements for constructing of cryptographically significant Boolean functions. Moreover, we provide a construction of Boolean functions (semi-bent Boolean functions) which can be used in the construction of orthogonal variable spreading factor codes used in code division multiple access (CDMA) systems as well as in certain cryptographic applications

Building a Sustainable Ecosystem for eHealth in Slovenia: Opportunities, Challenges, and Strategies

The pandemic COVID-19 has shown us how important it is for medical teams to have access to all patient data, to be able to implement appropriate guidelines, and to adapt as easily as possible to new challenges. This paper explores the implementation of an open platform within Slovenia’s healthcare backbone and identifies requisite elements for bolstering a national healthcare ecosystem. A gap analysis between the Slovenian open platform and Apperta’s specifications has revealed discrepancies. Through addressing this gap and examining backbone challenges, a preliminary list of success factors has been identified. These insights not only inform the establishment of a resilient national healthcare ecosystem but also contribute to a broader comprehension and execution of digital transformation within healthcare systems

Design methods for semi-bent functions

Semi-bent functions play an important role in the construction of orthogonal variable spreading factor codes used in code-division multiple-access (CDMA) systems as well as in certain cryptographic applications. In this article we provide several infinite classes of semi-bent functions, where each class is characterized by either a different decomposition of such a function with respect to the Walsh spectra of its subfunctions, or by the method used for its derivation. In particular, we also give the exact number of possibilities of decomposing bent functions, in a subclass of the Maiorana-McFarland class