An interactive guide to modern cryptography. From hash functions to post-quantum algorithms, the essential primitives and protocols that secure our digital world.
Primitives are the building blocks. Protocols are how they combine to create secure systems.
The Ingredients of Cryptography
Setting the stage: why cryptography matters and what you’ll learn.
Digital fingerprints that compress any data into fixed-length digests.
Ensuring data integrity and authenticity with shared secrets.
Where keys, nonces, and IVs come from. The foundation everything else depends on.
Block ciphers, stream ciphers, and modes of operation. Hiding data with shared keys.
Combining confidentiality and integrity in one operation.
Groups, fields, and the algebra that makes public-key cryptography possible.
Establishing shared secrets over insecure channels.
Public-key cryptography and hybrid encryption schemes.
The Recipes of Cryptography
Mathematical proof of authorship that anyone can verify.
Certificates, authorities, and the chains of trust that secure the internet.
TLS and the protocols protecting internet traffic.
When even the server can’t read your messages.
Passwords, tokens, and proving who you are.
Hash chains, Merkle trees, consensus, and crypto beyond encryption.
Post-quantum algorithms, zero-knowledge proofs, MPC, and homomorphic encryption.
Implementation bugs, side channels, key management failures, and how to avoid them.