Develop a greater intuition for the proper use of cryptography. This book teaches the basics of writing cryptographic algorithms in Python, demystifies cryptographic internals, and demonstrates common ways cryptography is used incorrectly.




Cryptography is the lifeblood of the digital world’s security infrastructure. From governments around the world to the average consumer, most communications are protected in some form or another by cryptography. These days, even Google searches are encrypted. Despite its ubiquity, cryptography is easy to misconfigure, misuse, and misunderstand.

Developers building cryptographic operations into their applications are not typically experts in the subject, and may not fully grasp the implication of different algorithms, modes, and other parameters. The concepts in this book are largely taught by example, including incorrect uses of cryptography and how "bad" cryptography can be broken. By digging into the guts of cryptography, you can experience what works, what doesn't, and why.






What You’ll Learn



Understand where cryptography is used, why, and how it gets misused

Know what secure hashing is used for and its basic properties
Get up to speed on algorithms and modes for block ciphers such as AES, and see how bad configurations break
Use message integrity and/or digital signatures to protect messages
Utilize modern symmetric ciphers such as AES-GCM and CHACHA
Practice the basics of public key cryptography, including ECDSA signatures
Discover how RSA encryption can be broken if insecure padding is used
Employ TLS connections for secure communications
Find out how certificates work and modern improvements such as certificate pinning and certificate transparency (CT) logs










































Who This Book Is For



IT administrators and software developers familiar with Python. Although readers may have some knowledge of cryptography, the book assumes that the reader is starting from scratch.