Decrypted Secrets Methods and Maxims of Cryptology

Cryptology, for millennia a "secret science", is rapidly gaining in practical importance for the protection of communication channels, databases, and software. Beside its role in computerized information systems (public key systems), more and more applications within computer systems and networks are appearing, which also extend to access rights and source file protection. The first part of this book treats secret codes and their uses - cryptography. The second part deals with the process of covertly decrypting a secret code - cryptanalysis - where in particular advice on assessing methods is given. The book presupposes only elementary mathematical knowledge. Spiced with a wealth of exciting, amusing, and sometimes personal stories from the history of cryptology, it will also interest general readers. Decrypted Secrets has become a standard book on cryptology. This 4th edition has again been revised and extended in many technical and biographical details.

Cryptography—The People.- Introductory Synopsis.- Aims and Methods of Cryptography.- Encryption Steps: Simple Substitution.- Encryption Steps: Polygraphic Substitution and Coding.- Encryption Steps: Linear Substitution.- Encryption Steps: Transposition.- Polyalphabetic Encryption: Families of Alphabets.- Polyalphabetic Encryption: Keys.- Composition of Classes of Methods.- Open Encryption Key Systems.- Encryption Security.- Cryptanalysis—The Machinery.- Exhausting Combinatorial Complexity.- Anatomy of Language: Patterns.- Polyalphabetic Case: Probable Words.- Anatomy of Language: Frequencies.- Kappa and Chi.- Periodicity Examination.- Alignment of Accompanying Alphabets.- Compromises.- Linear Basis Analysis.- Anagramming.- Concluding Remarks.