Enhanced descriptions from Syndetics:

Cryptology, for millennia a "secret science," is rapidly gaining in practical importance for the protection of communication channels, databases, & software. Beside its role in computerized information systems (public key systems), more & more applications within computer systems & networks are appearing, which also extend to access rights & source file protection. The first part of this book treats secret codes & 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, & sometimes personal stories from the history of cryptology, it will also interest general readers. Decrypted Secrets has become a standard book on cryptology. The new edition has been revised & extended in many details.

Table of contents provided by Syndetics

• Part I Cryptography (p. 1)
• 1 Introductory Synopsis (p. 8)
• 1.1 Cryptography and Steganography (p. 8)
• 1.2 Semagrams (p. 9)
• 1.3 Open Code: Masking (p. 12)
• 1.4 Cues (p. 16)
• 1.5 Open Code: Veiling by Nulls (p. 18)
• 1.6 Open Code: Veiling by Grilles (p. 22)
• 1.7 Classification of Cryptographic Methods (p. 24)
• 2 Aims and Methods of Cryptography (p. 25)
• 2.1 The Nature of Cryptography (p. 25)
• 2.2 Encryption (p. 31)
• 2.3 Cryptosystems (p. 33)
• 2.4 Polyphony (p. 35)
• 2.5 Character Sets (p. 37)
• 2.6 Keys (p. 40)
• 3 Encryption Steps: Simple Substitution (p. 42)
• 3.1 Case V^{{(1)}} \longrightarrow W (Unipartite Simple Substitutions) (p. 42)
• 3.2 Special Case V \longleftrightarrow V (Permutations) (p. 44)
• 3.3 Case V^{{(1)}} \longrightarrow W^m (Multipartite Simple Substitutions) (p. 51)
• 3.4 The General Case V^{{(1)}} \longrightarrow W^{{(m)}} , Straddling (p. 53)
• 4 Encryption Steps: Polygraphic Substitution and Coding (p. 56)
• 4.1 Case V^2 \longrightarrow W^{{(m)}} (Digraphic Substitutions) (p. 56)
• 4.2 Special Cases of Playfair and Delastelle: Tomographic Methods (p. 62)
• 4.3 Case V^3 \longrightarrow W^{{(m)}} (Trigraphic Substitutions) (p. 66)
• 4.4 The General Case V^{{(n)}} \longrightarrow W^{{(m)}} : Codes (p. 66)
• 5 Encryption Steps: Linear Substitution (p. 78)
• 5.1 Self-reciprocal Linear Substitutions (p. 80)
• 5.2 Homogeneous Linear Substitutions (p. 80)
• 5.3 Binary Linear Substitutions (p. 84)
• 5.4 GeneralLinear Substitutions (p. 84)
• 5.5 Decomposed Linear Substitutions (p. 85)
• 5.6 Decimated Alphabets (p. 88)
• 5.7 Linear Substitutions with Decimaland Binary Numbers (p. 89)
• 6 Encryption Steps: Transposition (p. 91)
• 6.1 Simplest Methods (p. 91)
• 6.2 Columnar Transpositions (p. 95)
• 6.3 Anagrams (p. 98)
• 7 Polyalphabetic Encryption: Families of Alphabets (p. 101)
• 7.1 Iterated Substitutions (p. 101)
• 7.2 Shifted and Rotated Alphabets (p. 102)
• 7.3 Rotor Crypto Machines (p. 105)
• 7.4 Shifted Standard Alphabets: Vigenère and Beaufort (p. 114)
• 7.5 Unrelated Alphabets (p. 118)
• 8 Polyalphabetic Encryption: Keys (p. 126)
• 8.1 Early Methods with Periodic Keys (p. 126)
• 8.2 `Double Key' (p. 128)
• 8.3 Vernam Encryption (p. 129)
• 8.4 Quasi-nonperiodic Keys (p. 131)
• 8.5 Machines that Generate Their Own Key Sequences (p. 132)
• 8.6 Off-Line Forming of Key Sequences (p. 143)
• 8.7 Nonperiodic Keys (p. 144)
• 8.8 Individual, One Time Keys (p. 148)
• 8.9 Key Negotiation and Key Management (p. 151)
• 9 Composition of Classes of Methods (p. 155)
• 9.1 Group Property (p. 155)
• 9.2 Superencryption (p. 157)
• 9.3 Similarity of Encryption Methods (p. 159)
• 9.4 Shannon's `Pastry Dough Mixing' (p. 160)
• 9.5 Confusion and Diffusion by ArithmeticalOperations (p. 166)
• 9.6 DES and IDEA (p. 170)
• 10 Open Encryption Key Systems (p. 179)
• 10.1 Symmetric and Asymmetric Encryption Methods (p. 180)
• 10.2 One-Way Functions (p. 182)
• 10.3 RSA Method (p. 189)
• 10.4 Cryptanalytic Attack upon RSA (p. 191)
• 10.5 Secrecy Versus Authentication (p. 194)
• 10.6 Security of Public Key Systems (p. 196)
• 11 Encryption Security (p. 197)
• 11.1 Cryptographic Faults (p. 197)
• 11.2 Maxims of Cryptology (p. 205)
• 11.3 Shannon's Yardsticks (p. 210)
• 11.4 Cryptology and Human Rights (p. 211)
• Part II Cryptanalysis (p. 217)
• 12 Exhausting Combinatorial Complexity (p. 220)
• 12.1 Monoalphabetic Simple Encryptions (p. 221)
• 12.2 Monoalphabetic Polygraphic Encryptions (p. 222)
• 12.3 Polyalphabetic Encryptions (p. 225)
• 12.4 GeneralRemarks on Combinatorial Complexity (p. 227)
• 12.5 Cryptanalysis by Exhaustion (p. 227)
• 12.6 Unicity Distance (p. 229)
• 12.7 Practical Execution of Exhaustion (p. 231)
• 12.8 Mechanizing the Exhaustion (p. 234)
• 13 Anatomy of Language: Patterns (p. 235)
• 13.1 Invariance of Repetition Patterns (p. 235)
• 13.2 Exclusion of Encryption Methods (p. 237)
• 13.3 Pattern Finding (p. 238)
• 13.4 Finding of Polygraphic Patterns (p. 242)
• 13.5 The Method of the Probable Word (p. 242)
• 13.6 Automatic Exhaustion of the Instantiations of a Pattern (p. 247)
• 13.7 Pangrams (p. 249)
• 14 Polyalphabetic Case: Probable Words (p. 251)
• 14.1 Non-Coincidence Exhaustion of Probable Word Position (p. 251)
• 14.2 Binary Non-Coincidence Exhaustion of Probable Word Position (p. 254)
• 14.3 The De Viaris Attack (p. 255)
• 14.4 Zig-Zag Exhaustion of Probable Word Position (p. 263)
• 14.5 The Method of Isomorphs (p. 264)
• 14.6 Covert Plaintext-Cryptotext Compromise (p. 270)
• 15 Anatomy of Language: Frequencies (p. 271)
• 15.1 Exclusion of Encryption Methods (p. 271)
• 15.2 Invariance of Partitions (p. 272)
• 15.3 Intuitive Method: Frequency Profile (p. 274)
• 15.4 Frequency Ordering (p. 275)
• 15.5 Cliques and Matching of Partitions (p. 278)
• 15.6 Optimal Matching (p. 284)
• 15.7 Frequency of Multigrams (p. 286)
• 15.8 The Combined Method of Frequency Matching (p. 291)
• 15.9 Frequency Matching for Polygraphic Substitutions (p. 297)
• 15.10 Free-Style Methods (p. 298)
• 15.11 Unicity Distance Revisited (p. 299)
• 16 Kappa and Chi (p. 301)
• 16.1 Definition and Invariance of Kappa (p. 301)
• 16.2 Definition and Invariance of Chi (p. 304)
• 16.3 The Kappa-Chi Theorem (p. 306)
• 16.4 The Kappa-Phi Theorem (p. 307)
• 16.5 Symmetric Functions of Character Frequencies (p. 309)
• 17 Periodicity Examination (p. 311)
• 17.1 The Kappa Test of Friedman (p. 312)
• 17.2 Kappa Test for Multigrams (p. 313)
• 17.3 Cryptanalysis by Machines (p. 314)
• 17.4 Kasiski Examination (p. 320)
• 17.5 Building a Depth and Phi Test of Kullback (p. 326)
• 17.6 Estimating the Period Length (p. 329)
• 18 Alignment of Accompanying Alphabets (p. 331)
• 18.1 Matching the Profile (p. 331)
• 18.2 Aligning Against Known Alphabet (p. 335)
• 18.3 Chi Test: Mutual Alignment of Accompanying Alphabets (p. 339)
• 18.4 Reconstruction of the Primary Alphabet (p. 344)
• 18.5 Kerckhoffs' Symmetry of Position (p. 346)
• 18.6 Stripping off Superencryption: Difference Method (p. 351)
• 18.7 Decryption of Code (p. 354)
• 18.8 Reconstruction of the Password (p. 354)
• 19 Compromises (p. 356)
• 19.1 Kerckhoffs' Superimposition (p. 356)
• 19.2 Superimposition for Encryptions with a Key Group (p. 358)
• 19.3 In-Phase Superimposition of Superencrypted Code (p. 373)
• 19.4 Cryptotext-Cryptotext Compromises (p. 376)
• 19.5 A Method of Sinkov (p. 381)
• 19.6 Cryptotext-Cryptotext Compromise: Doubling (p. 388)
• 19.7 Plaintext-Cryptotext Compromise: Feedback Cycle (p. 402)
• 20 Linear Basis Analysis (p. 412)
• 20.1 Reduction of Linear Polygraphic Substitutions (p. 412)
• 20.2 Reconstruction of the Key (p. 413)
• 20.3 Reconstruction of a Linear Shift Register (p. 414)
• 21 Anagramming (p. 417)
• 21.1 Transposition (p. 417)
• 21.2 Double Columnar Transposition (p. 420)
• 21.3 Multiple Anagramming (p. 420)
• 22 Concluding Remarks (p. 423)
• 22.1 Success in Breaking (p. 424)
• 22.2 Mode of Operation of the Unauthorized Decryptor (p. 429)
• 22.3 Illusory Security (p. 434)
• 22.4 Importance of Cryptology (p. 435)
• Appendix: Axiomatic Information Theory (p. 438)
• Bibliography (p. 448)
• Index (p. 451)
• Photo Credits (p. 471)