Thirty years ago, cryptography was the almost exclusive preserve of the Government and Military. Today it is the key technology underlying the Internet revolution and is of critical commercial and academic importance. The broadband technology necessary to make Internet commerce a reality is already with us, but the best networks in the world are effectively useless if no one will trust them with their sensitive commercial, financial, medical or military data. Most books on cryptography are written by mathematicians for mathematicians and assume more background knowledge than many are likely to possess. This book redresses this balance with self-contained, tutorial-styled chapters plus worked examples. Completion of the sequencing of the Human Genome has opened new doors in the treatment of disease. This book suggests it will be cryptographers not medics who will make critical advances. CONTENTS: Chapter 1: Introduction; Chapter 2: Factoring with elliptic curves; Chapter 3: Factoring with falsewitnesses; Chapter 4: The nongroup; Chapter 5: Mixed shift register sequences; Chapter 6: Finite automata Chapter 7: Diophantine public key ciphers; Chapter 8: Feedforward sequences; Chapter 9: Spectral cryptanalysis; Chapter 10: Ramanujan's partition function; Chapter 11: Cryptanalysis of the human genome; Chapter 12: On the absolute limit of computation; Bibliography; Index. READERSHIP: Cryptography Students, (Final Year Undergraduates, MSc), Researchers in crypto and computer security, Financial security managers, E-commerce entrepreneurs.