In addition, new issues have emerged which did not exist before, for example Cryptology discuss issues above - it's on the basis of all information security. Fundamentals of Cryptology serves as an introduction to the methods of modern cryptography. Second, this book presents the public key cryptography, which allows to protect data without a prearranged key. Fundamentals of Cryptology is an updated and improved version of Introduction to Cryptology, originally published in 1988. In addition to the revision of existing material, there is a new section, and two new chapters on elliptic curves and authentication codes, respectively. Fundamentals of Cryptology will attract computer scientists, mathematicians, and researchers, students, and practitioners in the field of cryptography.