This book offers an introduction to post-quantum cryptography for students, engineers and researchers in the field of information security. Above all, it describes the mathematical concepts underlying the security of post-quantum cryptographic schemes. The first part of the book provides essential background information by briefly introducing the core elements of quantum computation and presenting Shor's algorithm, which solves the factoring problem and the discrete logarithm problem in polynomial time. In turn, the second part presents a number of candidates for post-quantum public-key encryption and digital signature schemes. The security of these schemes is based on mathematical problems in coding theory, multivariate quadratic equations, and lattices, respectively. The book provides an essential guide for students, researchers and engineers, helping them to quickly grasp this highly promising area of cryptography.