Cryptography

Learn how to program in Python while making and breaking ciphers—algorithms used to create and send secret messages!

After a crash course in Python programming basics, you’ll learn to make, test, and hack programs that encrypt text with classical ciphers like the transposition cipher and Vigenère cipher. You’ll begin with simple programs for the reverse and Caesar ciphers and then work your way up to public key cryptography, the type of encryption used to secure today’s online transactions, including digital signatures, email, and Bitcoin.

Each program includes the full code and a line-by-line explanation of how things work. By the end of the book, you’ll have learned how to code in Python and you’ll have the clever programs to prove it!

You’ll also learn how to:

• Combine loops, variables, and flow control statements into real working programs
• Use dictionary files to instantly detect whether decrypted messages are valid English or gibberish
• Create test programs to make sure that your code encrypts and decrypts correctly
• Code (and hack!) a working example of the affine cipher, which uses modular arithmetic to encrypt a message
• Break ciphers with techniques such as brute-force and frequency analysis

There’s no better way to learn to code than to play with real programs. Cracking Codes with Python makes the learning fun!

Cryptography from A5/0 to ZRTP

Expand your mind—and your crypto knowledge—with the ultimate desktop dictionary for all things cryptography. Written by a globally recognized cryptographer for fellow experts and novices to the field alike, Crypto Dictionary is rigorous in its definitions, yet easy to read and laced with humor. You’ll find:

• A survey of crypto algorithms both widespread and niche, from RSA and DES to the USSR’s GOST cipher

• Trivia from the history of cryptography, such as the MINERVA backdoor in Crypto AG’s encryption algorithms, which may have let the US read the secret communications of foreign governments

• An explanation of why the reference to the Blowfish cipher in the TV show 24 makes absolutely no sense

• Discussions of numerous cryptographic attacks, like the slide attack and biclique attack (and the meaning of a crypto “attack”)

• Types of cryptographic proofs, such as zero-knowledge proofs of spacetime

• A polemic against referring to cryptocurrency as “crypto”

• A look toward the future of cryptography, with discussions of the threat of quantum computing poses to our current cryptosystems and a nod to post-quantum algorithms, such as lattice-based cryptographic schemes

Or, flip to any random page and learn something new, interesting, and mind-boggling for fun. Organized alphabetically, with hundreds of incisive entries and illustrations at your fingertips, Crypto Dictionary is the crypto world go-to guide that you’ll always want within reach.

An all-practical guide to the cryptography behind common tools and protocols that will help you make excellent security choices for your systems and applications.

In Real-World Cryptography, you will find:

• Best practices for using cryptography
• Diagrams and explanations of cryptographic algorithms
• Implementing digital signatures and zero-knowledge proofs
• Specialized hardware for attacks and highly adversarial environments
• Identifying and fixing bad practices
• Choosing the right cryptographic tool for any problem

Real-World Cryptography reveals the cryptographic techniques that drive the security of web APIs, registering and logging in users, and even the blockchain. You’ll learn how these techniques power modern security, and how to apply them to your own projects. Alongside modern methods, the book also anticipates the future of cryptography, diving into emerging and cutting-edge advances such as cryptocurrencies, and post-quantum cryptography. All techniques are fully illustrated with diagrams and examples so you can easily see how to put them into practice.

Explore the fascinating and rich world of Secret Key cryptography! This book provides practical methods for encrypting messages, an interesting and entertaining historical perspective, and an incredible collection of ciphers and codes—including 30 unbreakable methods.

In Secret Key Cryptography: Ciphers, from simple to unbreakable you will:

• Measure the strength of your ciphers and learn how to guarantee their security
• Construct and incorporate data-compression codes
• Generate true random numbers in bulk
• Construct huge primes and safe primes
• Add an undetectable backdoor to a cipher
• Defeat hypothetical ultracomputers that could be developed decades from now
• Construct 30 unbreakable ciphers

Secret Key Cryptography gives you a toolbox of cryptographic techniques and Secret Key methods. The book’s simple, non-technical language is easy to understand and accessible for any reader, even without the advanced mathematics normally required for cryptography. You’ll learn how to create and solve ciphers, as well as how to measure their strength. As you go, you’ll explore both historic ciphers and groundbreaking new approaches—including a never-before-seen way to implement the uncrackable One-Time Pad algorithm.

Whoever you are, this book is for you! History buffs will love seeing the evolution of sophisticated cryptographic methods, hobbyists will get a gentle introduction to cryptography, and engineers and computer scientists will learn the principles of constructing secure ciphers. Even professional cryptographers will find a range of new methods and concepts never published before.

This practical guide to modern encryption breaks down the fundamental mathematical concepts at the heart of cryptography without shying away from meaty discussions of how they work. You’ll learn about authenticated encryption, secure randomness, hash functions, block ciphers, and public-key techniques such as RSA and elliptic curve cryptography.

You'll also learn:

• Key concepts in cryptography, such as computational security, attacker models, and forward secrecy
• The strengths and limitations of the TLS protocol behind HTTPS secure websites
• Quantum computation and post-quantum cryptography
• About various vulnerabilities by examining numerous code examples and use cases
• How to choose the best algorithm or protocol and ask vendors the right questions

Each chapter includes a discussion of common implementation mistakes using real-world examples and details what could go wrong and how to avoid these pitfalls.

Whether you’re a seasoned practitioner or a beginner looking to dive into the field, Serious Cryptography will provide a complete survey of modern encryption and its applications.