From the reviews: “The book offers a detailed overview of the main intractable problems which ensure security of usual cryptosystems … and the way to solve them using quantum calculus. … It can be very well used as a course for undergraduate students, many notions being self-contained … . book is very interesting, easily to be followed, pedagogically constructed. It offers a good source of information, being an excellent support for students and researchers who wish to find general details about the new paradigm of computation … .” (Adrian Atanasiu, zbMATH, Vol. 1273, 2013)