A Classical Introduction to Modern Cryptography: Applications for Communications Security introduces fundamentals of information and communication security by providing appropriate mathematical concepts to prove or break the security of cryptographic schemes. This advanced-level textbook covers conventional cryptographic primitives and cryptanalysis of these primitives; basic algebra and number theory for cryptologists; public key cryptography and cryptanalysis of these schemes; and other cryptographic protocols, e.g. secret sharing, zero-knowledge proofs and undeniable signature schemes. A Classical Introduction to Modern Cryptography: Applications for Communications Security is rich with algorithms, such as exhaustive search with time/memory tradeoffs; proofs, such as security proofs for DSA-like signature schemes; and classical attacks such as collision attacks on MD4. Hard-to-find standards, e.g. SSH2 and security in Bluetooth, are also included.