Consists of three consecutive parts: 1. Basic Concepts of Computability. 2. Traditional Recursion Theory. 3. Unified Type 2 theory of constructivity and computability on Baire's space including a general the- ory of representations.

In addition, they appear in algorithms analysis and in the bulk of discrete mathematics taught to computer scientists. This book is devoted to the background of these methods.

These two areas have still huge influence on our lives and our world. The theory of Petri Nets is still developing: some directions of investigations are presented in section 3.

Consists of three consecutive parts: 1. Basic Concepts of Computability. 2. Traditional Recursion Theory. 3. Unified Type 2 theory of constructivity and computability on Baire's space including a general the- ory of representations.

This book, benefiting from the author's research and teaching experience in Algorithmic Information Theory (AIT), should help to make the detailed mathematical techniques of AIT accessible to a much wider audience.

This book gives a broad overview of public-key cryptography, covering its essence and advantages, various public-key cryptosystems and protocols. It also gives a comprehensive introduction to classical cryptography and cryptanalysis.