This group is for discussion of the unsolved problems in number theory, logic, and cryptography which are featured on the web site

http://UnsolvedProblems.org

Problems include the existence (or otherwise) of a perfect cuboid, the chromatic number of the plane, the discrete log problem, Grimm's conjecture, the ABC conjecture, Diffie-Hellman, the Goldbach conjecture, the twin primes conjecture, the Dorabella cipher (aka the Elgar cipher), the RSA challenge, the existence (or otherwise) of an odd perfect number, the existence (or otherwise) of a magic square of squares, the Collatz conjecture, the Beal conjecture, Legendre's conjecture, the Riemann hypothesis, the Zodiac 340 cipher, and the Voynich manuscript, amongst others.

The web site describes the problems and offers potential solvers the opportunity to have their solutions published, while this group facilitates questions and discussion.