Math & Cryptography Olympiad Open To All
NSUCRYPTO is an online contest that asks participants to solve tough problems. It has already taken place four times and all its previous problems and their solutions are available. Not all its problems have been solved, however, as this contest is looking for breakthroughs in hard scientific problems of modern cryptography.
Source: Sue Gee
The Olympiad is organized by Novosibirsk State University, Sobolev Institute of Mathematics (Novosibirsk), Tomsk State University, Belarusian State University and University of Leuven, Belgium. When it was first held, in November 2014, it was as the First Siberian Student’s Olympiad in Cryptography with International participation and it    attracted over 450 participants from 12 countries and all but one of the winners came from Russia, with the exception being a team from Leuven.
Explaining the reasons for organizing this Olympiad    and its aims, the paper written outlining the experience of the first event states:
There exist several school competitions in cryptography and information security, but this one is the first cryptographic Olympiad for students and professionals. The aim of the Olympiad was to involve students and young researchers in solving the curious and hard scientific problems of the modern cryptography. From the very beginning, the concept was not to stop on the training olympic tasks but to include unsolved research problems at the intersection of mathematics and cryptography.
There are no restrictions on age or status for this contest. At registration participants choose one of three categories, each of which has prizes:
"school student" - for junior researchers: pupils and school students
"university student" - for participants who are currently studying at universities
"professional" - for participants who have already completed education or just want to be in the restriction-free category
The language for the contest is English although solutions can also be written in Russian.
The blurb states:
We accept solutions in any electronic format (pdf, jpg, txt, rtf, docx, tex, etc). For example a participant is able to write his solutions on paper and send us a picture (please check that a picture is of a good quality). Solutions should have been written with all necessary details. Submit your files through your personal account on our website.
The Olympiad has two independent rounds. In the first round, which has a duration of 4 hours 30 minutes, there are two sections: A & B. Problems, six in total, in section A are for participants in the "school student" category; the seven B problems are for participants registered as university students and professional.
The second round last a weeks and is for teams to tackle research and programming problems in cryptography with prizes for winners in each category and special prizes for coming up with a solution for a problem flagged as unsolved.
I came across this challenge - the next one of which takes place starting on Ocober 14, 2018, via the paper Problems and solutions of the Fourth International Students' Olympiad in Cryptography NSUCRYPTO. As well as being here on arXv, it is also reproduced on the Archive section of the NSUCRYPTO website. From this paper I discovered that over four years it had attracted 1300 participants from 24 countries and the website's Results also reveals that prizes have been won from around the world, including the UK, Germany, Iran, China, Vietnam and South Africa.
Choosing some sample problems was difficult as they are all interesting and are very varied. This one is a Round 1 Set A question - for school students and is a variant on a classic puzzle:
We have three closed chests. Some of them contain the treasures (diamonds, gold coins, bitcoins as well) but we do not know which ones. A parrot knows which chests contain the treasures and which do not; he agrees to answer to questions by “yes” or “no”. He may possibly lie in his answers but not more than once. List six questions such that it is possible to deduce from the answers of the parrot which chests contain the treasures and which do not.
There's a more difficult version of this in the B Set with seven chests, a parrot who lies not more than twice and 15 questions.
The Music Lover question was common to both A and B sets and requires mapping one code to another:
If you want the solutions and lots more problems, and perhaps want to register to take part in future Olympiad's, make your way to:
You'll also find details of the unsolved problems on this site and some very positive feedback from participants. Again, choosing just two to quote:
NSUCRYPTO is an excellent contest: the problems are challenging, varied and intriguing and a unique combination of mathematics and computation are required. Its a contest that leaves you wanting to spend more time on it after the deadline, just to work out the questions you didn't get. I thoroughly enjoyed participating last year and am much anticipating the questions of this year.
Robert Spencer (South Africa, University of Cape Town)
The tasks of NSUCRYPTO are remarkable for a great variety: they range from tricky puzzles to really hard or even unsolved programming and mathematical problems. Every year there were several tasks representing not only some modern cryptographic algorithms but the related research problems. Participation in the Olympiad offers you an excellent opportunity to try yourself as a codebreaker and a cryptographer.