Introduction to Cryptography: History, Significance, and Future Directions

The book is a popular‑science work on cryptography that surveys ancient, classical, modern, and future cryptographic systems, illustrating how codes have shaped politics, warfare, and everyday life throughout human history.

It defines a "code" broadly as any meaningful human‑made symbol—sound, text, image, gesture, etc.—and explains that secrecy is both relative (unknown to most) and absolute (potentially unknowable to everyone).

By viewing all symbol systems as codes, the author argues that understanding cryptography is essential for anyone, regardless of profession.

The narrative connects cryptographic practices to human nature and the selfish‑gene theory, suggesting that the desire to protect or acquire information drives the creation and breaking of codes.

In a communication cryptosystem, three roles are identified: the encoder (encryptor), the decoder (decryptor) who possesses the key, and the codebreaker who attempts decryption without a key, each facing distinct challenges.

The text stresses that no algorithmic cryptosystem is absolutely secure—every system can theoretically be broken—yet cryptography remains a crucial tool of war and espionage.

The evolution of communication cryptography mirrors advances in communication technology, progressing from classical and mechanical codes to electronic, quantum, and emerging DNA‑computing cryptography.

The book’s structure includes chapters on foreign and Chinese classical codes, World War I and II codes, mechanical and modern codes, a forward‑looking chapter on quantum and anti‑quantum cryptography, a section on Chinese character codes, and a concluding perspective on a universal decryption framework.

The author, former vice‑president of the Chinese Cryptology Society, aims to produce a work that is accessible to lay readers yet insightful for experts, hoping it will be evaluated favorably by reviewers.