Cryptography Resources
This section is mainly for the people looking to dive into cryptography and the underlying math, not really for basic concepts like "What is GPG?" or "How do I use OpenSSL?". These questions are valid, but you might just want to hit up Google for that.
Books
- Serious Cryptography is a very good book to introduce fundamental concepts
- An Introduction to Mathematical Cryptography is an intro-level, proofs-based book on some cryptographic concepts. Technically costs $50, but you can always find it ;)
- A Graduate Course in Applied Cryptography is free and should be read after Intro to Mathematical Cryptography
Challenge Platforms and Others
- CryptoHack is a gamified platform exclusively for cryptography and cryptanalysis. Very, very smart people over in their Discord - 100% recommend this.
- CryptoPals is a collection of cryptography exercises which are very programming-oriented (e.g. making you write your own frequency analysis, writing a padding oracle attack)
- MysteryTwisterC3 focuses more on crypto design and didactical aspects (like a tutorial in differential cryptanalysis) and it includes many challenges with historic or "obscure" procedures and machines (like HandyCipher or Sigaba).
- Dan Boneh's Cryptography Course is another resource to learn the subject