The Fifth International Students' Olympiad in Cryptography -- NSUCRYPTO: problems and their solutions
This work documents educational and research challenges for students and researchers in cryptography, but it is incremental as it compiles existing competition materials.
The paper presents problems and solutions from the Fifth International Students' Olympiad in Cryptography (NSUCRYPTO'2018), covering topics such as attacks on ciphers, Boolean functions, and quantum circuits, and includes a complete solution to an open problem on invertible Sylvester matrices.
Problems and their solutions of the Fifth International Students' Olympiad in cryptography NSUCRYPTO'2018 are presented. We consider problems related to attacks on ciphers and hash functions, Boolean functions, quantum circuits, Enigma, etc. We discuss several open problems on orthogonal arrays, Sylvester matrices and disjunct matrices. The problem of existing an invertible Sylvester matrix whose inverse is again a Sylvester matrix was completely solved during the Olympiad.